Editor: live settings sync + session-death banner

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/bun/edits.ts

@@ -134,6 +134,21 @@ export class EditManager {
 		});
 	}
 
+	/**
+	 * Park unsaveable editor content (window closed, session dead) in the
+	 * leftovers dir so the next-boot prompt offers it back to the user.
+	 */
+	async rescueDraft(name: string, content: string): Promise<void> {
+		const dir = path.join(this.editsDir, crypto.randomUUID().slice(0, 8));
+		await fs.mkdir(dir, { recursive: true });
+		await fs.writeFile(
+			path.join(dir, "meta.json"),
+			JSON.stringify({ name, rescuedAt: new Date().toISOString() }),
+		);
+		await fs.writeFile(path.join(dir, name), content, "utf8");
+		console.log(`[edit] rescued unsaved draft of ${name} -> ${dir}`);
+	}
+
 	/** Session gone (disconnect, tab close, death): stop its watchers, drop temps. */
 	stopForSession(sessionId: string): void {
 		const [mine, rest] = [

src/bun/index.ts

@@ -1,8 +1,10 @@
 import Electrobun, { ApplicationMenu, BrowserWindow, Updater, Utils } from "electrobun/bun";
 import { BRANDING } from "../shared/branding";
-import { effectiveConcurrency } from "../shared/types";
+import type { EditorOpenContext } from "../shared/rpc";
+import { effectiveConcurrency, type AppSettings } from "../shared/types";
 import { PanelContextMenu } from "./context-menu";
 import { EditManager } from "./edits";
+import { EditorWindows } from "./editor-windows";
 import { SessionRegistry } from "./fs/registry";
 import { applyApplicationMenu } from "./menu";
 import { createAppRPC } from "./rpc-handlers";
@@ -11,6 +13,7 @@ import { migrateLegacyDataDir } from "./store/paths";
 import { SettingsStore } from "./store/settings";
 import { AppTray } from "./tray";
 import { TransferEngine } from "./transfers/engine";
+import { buildPreload } from "./windows";
 
 const PROD_URL = "views://app/index.html";
 
@@ -44,6 +47,8 @@ const contextMenu = new PanelContextMenu();
 const events = {
 	sessionClosed: (_info: { sessionId: string; reason: string }) => {},
 	connectionsChanged: () => {},
+	openEditor: (_ctx: EditorOpenContext) => {},
+	settingsChanged: (_settings: AppSettings) => {},
 };
 const rpc = createAppRPC({ registry, engine, store, settings, edits, contextMenu, events });
 const url = await getMainViewUrl();
@@ -66,10 +71,23 @@ const win = new BrowserWindow({
 		? { titleBarStyle: "hiddenInset" as const, trafficLightOffset: { x: 12, y: 13 } }
 		: {}),
 	// lets the UI pick the fused layout before first paint
-	preload: `window.__APP_PLATFORM=${JSON.stringify(process.platform)};`,
+	preload: buildPreload("main"),
 	rpc,
 });
 
+const editors = new EditorWindows({
+	registry,
+	settings,
+	edits,
+	url,
+	mainFrame: () => win.getFrame(),
+	notifyMain: { pathRefresh: (info) => rpc.send.pathRefresh(info) },
+});
+events.openEditor = (ctx) => editors.open(ctx);
+events.settingsChanged = (s) => editors.broadcastSettings(s);
+// clean editors close with the main window; dirty ones get to ask first
+win.on("close", () => editors.closeAllForAppExit());
+
 new AppTray(win);
 contextMenu.onAction = (action) => rpc.send.menuAction({ action });
 
@@ -85,7 +103,11 @@ engine.onUpdate = (snapshot) => {
 	const previous = notifiedStates.get(snapshot.id);
 	if (previous !== snapshot.state) {
 		notifiedStates.set(snapshot.id, snapshot.state);
-		if (!windowFocused && (snapshot.state === "completed" || snapshot.state === "failed")) {
+		if (
+			!windowFocused &&
+			!editors.anyFocused() &&
+			(snapshot.state === "completed" || snapshot.state === "failed")
+		) {
 			Utils.showNotification({
 				title: snapshot.state === "completed" ? "Transfer complete" : "Transfer failed",
 				body:
@@ -102,18 +124,24 @@ engine.onUpdate = (snapshot) => {
 	}
 };
 
-// don't quit out from under running transfers
+// don't quit out from under running transfers or unsaved editors
 let quitConfirmed = false;
 Electrobun.events.on("before-quit", (event) => {
-	if (quitConfirmed || !engine.hasActiveJobs()) return;
+	const transfers = engine.activeJobCount();
+	const dirtyEditors = editors.dirtyCount();
+	if (quitConfirmed || (transfers === 0 && dirtyEditors === 0)) return;
 	(event as { response: { allow: boolean } }).response = { allow: false };
 	void (async () => {
-		const count = engine.activeJobCount();
+		const parts = [
+			transfers > 0 && `${transfers} transfer${transfers === 1 ? " is" : "s are"} still running`,
+			dirtyEditors > 0 &&
+				`${dirtyEditors} file${dirtyEditors === 1 ? " has" : "s have"} unsaved changes`,
+		].filter(Boolean);
 		const { response } = await Utils.showMessageBox({
 			type: "warning",
 			title: BRANDING.appName,
-			message: `${count} transfer${count === 1 ? " is" : "s are"} still running.`,
+			message: `${parts.join(" and ")}.`,
-			detail: "Quitting now will abort them.",
+			detail: "Quitting now will abort transfers and discard unsaved changes.",
 			buttons: ["Quit Anyway", "Cancel"],
 			defaultId: 1,
 			cancelId: 1,
@@ -124,14 +152,28 @@ Electrobun.events.on("before-quit", (event) => {
 		}
 	})();
 });
-events.sessionClosed = (info) => rpc.send.sessionClosed(info);
+events.sessionClosed = (info) => {
+	rpc.send.sessionClosed(info);
+	editors.notifySessionClosed(info);
+};
 events.connectionsChanged = () => void applyApplicationMenu(store);
 void settings.load().then((s) => engine.setConcurrency(effectiveConcurrency(s)));
 
 void applyApplicationMenu(store);
 ApplicationMenu.on("application-menu-clicked", (event) => {
 	const action = (event as { data?: { action?: string } }).data?.action;
-	if (action) rpc.send.menuAction({ action });
+	if (!action) return;
+	// ⌘W while an editor window is focused closes that editor (with its dirty
+	// prompt), not a main-window tab. Other menu actions deliberately still
+	// target the main window.
+	if (action === "close-tab") {
+		const focusedEditor = editors.focusedKey();
+		if (focusedEditor) {
+			editors.requestClose(focusedEditor);
+			return;
+		}
+	}
+	rpc.send.menuAction({ action });
 });
 
 console.log(`${BRANDING.appName} started (${url})`);

src/bun/rpc-handlers.ts

@@ -1,6 +1,6 @@
 import { BrowserView, Utils } from "electrobun/bun";
-import type { AppRPC } from "../shared/rpc";
+import type { AppRPC, EditorOpenContext } from "../shared/rpc";
-import { effectiveConcurrency, type Result } from "../shared/types";
+import { effectiveConcurrency, type AppSettings, type Result } from "../shared/types";
 import type { PanelContextMenu } from "./context-menu";
 import { readFileText, writeFileText, type EditManager } from "./edits";
 import type { SessionRegistry } from "./fs/registry";
@@ -27,6 +27,8 @@ export interface AppDeps {
 	events: {
 		sessionClosed: (info: { sessionId: string; reason: string }) => void;
 		connectionsChanged: () => void;
+		openEditor: (ctx: EditorOpenContext) => void;
+		settingsChanged: (settings: AppSettings) => void;
 	};
 }
 
@@ -195,6 +197,7 @@ export function createAppRPC({
 					wrap(async () => {
 						await settings.save(next);
 						engine.setConcurrency(effectiveConcurrency(next));
+						events.settingsChanged(next);
 						return {};
 					}),
 
@@ -261,6 +264,64 @@ export function createAppRPC({
 						Utils.moveToTrash(path);
 						return {};
 					}),
+
+				// ---- editor windows ----
+				openEditor: (ctx) =>
+					wrap(async () => {
+						events.openEditor(ctx);
+						return {};
+					}),
+			},
+		},
+	});
+}
+
+export interface EditorRpcHooks {
+	ctx: EditorOpenContext;
+	/** Draft mirror tick: store dirty flag + content on the window record. */
+	onDraft: (state: { dirty: boolean; content: string }) => void;
+	/** editorSave succeeded: clean the record, retitle, refresh main panels. */
+	onSaved: () => void;
+	/** Webview resolved its dirty prompt: close without the native fallback. */
+	onCloseConfirmed: () => void;
+}
+
+/**
+ * RPC for one editor window. Each window MUST get its own instance (binding a
+ * BrowserView steals the rpc's transport), and the hooks close over that
+ * window's record — no ids on the wire.
+ */
+export function createEditorRPC(
+	deps: { registry: SessionRegistry; settings: SettingsStore },
+	hooks: EditorRpcHooks,
+) {
+	return BrowserView.defineRPC<AppRPC>({
+		maxRequestTime: MAX_REQUEST_TIME_MS,
+		handlers: {
+			requests: {
+				readFile: ({ sessionId, path }) =>
+					wrap(async () => ({
+						content: await readFileText(deps.registry.get(sessionId), path),
+					})),
+
+				getSettings: () => wrap(async () => ({ settings: await deps.settings.load() })),
+
+				editorSave: ({ content }) =>
+					wrap(async () => {
+						const { sessionId, path } = hooks.ctx;
+						await writeFileText(deps.registry.get(sessionId), path, content);
+						hooks.onSaved();
+						return {};
+					}),
+
+				editorClose: () =>
+					wrap(async () => {
+						hooks.onCloseConfirmed();
+						return {};
+					}),
+			},
+			messages: {
+				editorState: (state) => hooks.onDraft(state),
 			},
 		},
 	});

src/bun/windows.ts

@@ -0,0 +1,121 @@
+import { BrowserWindow } from "electrobun/bun";
+
+const isMac = process.platform === "darwin";
+
+/**
+ * The preload globals every window gets. Single composition point: the UI
+ * reads them in ui/src/app/platform.ts before first paint (window chrome and
+ * root-component selection both depend on them).
+ */
+export function buildPreload(mode: "main" | "editor", ctx?: unknown): string {
+	let script =
+		`window.__APP_PLATFORM=${JSON.stringify(process.platform)};` +
+		`window.__APP_MODE=${JSON.stringify(mode)};`;
+	if (ctx !== undefined) script += `window.__APP_CTX=${JSON.stringify(ctx)};`;
+	return script;
+}
+
+export interface SecondaryWindowOptions {
+	title: string;
+	/** The once-resolved dev/prod url (see getMainViewUrl in index.ts). */
+	url: string;
+	mode: "editor"; // widens when more window kinds exist (connection manager…)
+	ctx?: unknown;
+	frame: { x: number; y: number; width: number; height: number };
+	/** Per-window rpc instance. NEVER share one across windows — each
+	 *  BrowserView steals the rpc's transport when it binds. */
+	rpc: NonNullable<ConstructorParameters<typeof BrowserWindow>[0]>["rpc"];
+}
+
+/**
+ * App-chromed secondary window.
+ *
+ * PORTABILITY: the only spot that branches on platform for secondary-window
+ * chrome. macOS fuses the titlebar (traffic lights overlay the UI's h-10
+ * header row, same treatment as the main window); Windows/Linux keep the
+ * native titlebar and the UI renders a compact non-drag header instead.
+ */
+export function openSecondaryWindow(opts: SecondaryWindowOptions): BrowserWindow {
+	return new BrowserWindow({
+		title: opts.title,
+		url: opts.url,
+		frame: opts.frame,
+		...(isMac
+			? { titleBarStyle: "hiddenInset" as const, trafficLightOffset: { x: 12, y: 13 } }
+			: {}),
+		preload: buildPreload(opts.mode, opts.ctx),
+		rpc: opts.rpc,
+	});
+}
+
+/**
+ * Keyed registry of secondary windows: dedupe/activate, cascade placement off
+ * an anchor window, focus tracking, close cleanup. A future "window follows
+ * window" grouping step slots in here — the registry already owns the window
+ * handles and the anchor it would need (anchor.on('move') + setPosition).
+ */
+export class WindowRegistry<Rec extends { win: BrowserWindow }> {
+	private records = new Map<string, Rec>();
+	private focused = new Set<string>();
+	private opened = 0;
+
+	constructor(private anchorFrame: () => { x: number; y: number }) {}
+
+	get(key: string): Rec | undefined {
+		return this.records.get(key);
+	}
+
+	/** True (and focuses the window) when the key already has a live window. */
+	activateExisting(key: string): boolean {
+		const rec = this.records.get(key);
+		if (!rec) return false;
+		rec.win.activate();
+		return true;
+	}
+
+	set(key: string, rec: Rec): void {
+		this.records.set(key, rec);
+	}
+
+	/** Cascade off the anchor so stacked windows never hide each other fully. */
+	nextFrame(width: number, height: number): { x: number; y: number; width: number; height: number } {
+		const anchor = this.anchorFrame();
+		const step = (this.opened++ % 8) * 28;
+		return { x: anchor.x + 90 + step, y: anchor.y + 70 + step, width, height };
+	}
+
+	/**
+	 * Wire close/focus/blur for a window. electrobun's emitter has no off(),
+	 * so these closures capture only (this, key) — never the record — letting
+	 * closed-window content be garbage collected after delete().
+	 */
+	track(key: string, win: BrowserWindow, onClose: (key: string) => void): void {
+		win.on("focus", () => this.focused.add(key));
+		win.on("blur", () => this.focused.delete(key));
+		win.on("close", () => {
+			this.focused.delete(key);
+			onClose(key);
+		});
+	}
+
+	delete(key: string): void {
+		this.records.delete(key);
+	}
+
+	anyFocused(): boolean {
+		return this.focused.size > 0;
+	}
+
+	focusedKey(): string | null {
+		for (const key of this.focused) return key;
+		return null;
+	}
+
+	forEach(fn: (rec: Rec, key: string) => void): void {
+		for (const [key, rec] of this.records) fn(rec, key);
+	}
+
+	size(): number {
+		return this.records.size;
+	}
+}

src/shared/rpc.ts

@@ -11,12 +11,24 @@ import type {
 	TransferSnapshot,
 } from "./types";
 
+/** Everything an editor window needs to know about the file it hosts. */
+export interface EditorOpenContext {
+	sessionId: string;
+	path: string;
+	name: string;
+	sessionTitle: string;
+}
+
 // Structurally equivalent to electrobun's ElectrobunRPCSchema, written in
 // resolved form so this file stays importable from the Angular bundle without
 // pulling in bun-only type modules.
 //
 // bun.requests    = calls the webview makes, handled in src/bun/rpc-handlers.ts
 // webview.messages = push events from bun, handled in ui rpc.service.ts
+//
+// ONE schema serves both window kinds (main + editor): electrobun allows
+// partial handler sets, and messages nobody listens to are silently dropped,
+// so each side only implements/hears what applies to it.
 export type AppRPC = {
 	bun: {
 		requests: {
@@ -122,8 +134,17 @@ export type AppRPC = {
 				response: Result;
 			};
 			moveToTrash: { params: { path: string }; response: Result };
+			// editor windows
+			/** Main window only: open (or focus) a native editor window. */
+			openEditor: { params: EditorOpenContext; response: Result };
+			/** Editor windows only — handled by that window's own rpc closure. */
+			editorSave: { params: { content: string }; response: Result };
+			editorClose: { params: Record<string, never>; response: Result };
+		};
+		messages: {
+			/** Editor → bun draft mirror; safety net for the non-cancellable native close. */
+			editorState: { dirty: boolean; content: string };
 		};
-		messages: Record<never, never>;
 	};
 	webview: {
 		requests: Record<never, never>;
@@ -131,6 +152,12 @@ export type AppRPC = {
 			transferUpdate: TransferSnapshot;
 			sessionClosed: { sessionId: string; reason: string };
 			menuAction: { action: string };
+			/** bun → editor windows when the main window saves settings. */
+			settingsChanged: { settings: AppSettings };
+			/** bun → main after an editor save, so matching panels refresh. */
+			pathRefresh: { sessionId: string; dir: string };
+			/** bun → one editor: run the in-window close flow (dirty prompt). */
+			editorCloseRequest: Record<string, never>;
 		};
 	};
 };

ui/src/app/app.html

@@ -37,39 +37,6 @@
   @if (dialogs.overwrite(); as req) {
     <app-overwrite-dialog [request]="req" />
   }
-  @if (dialogs.editor(); as req) {
-    <app-editor-dialog [request]="req" />
-  }
 
-  <!-- toasts -->
+  <app-toasts />
-  <div class="pointer-events-none fixed right-3 bottom-8 z-50 flex w-80 flex-col gap-2">
-    @for (t of toast.toasts(); track t.id) {
-      <div
-        (mouseenter)="toast.pause(t.id)"
-        (mouseleave)="toast.resume(t.id)"
-        class="group pointer-events-auto relative flex items-start gap-2 overflow-hidden rounded-lg border border-border bg-card p-3 text-xs text-card-foreground shadow-lg"
-      >
-        <ng-icon
-          [name]="toastIcon(t.kind)"
-          size="1rem"
-          [class]="t.kind === 'error' ? 'shrink-0 text-destructive' : 'shrink-0 text-success'"
-        />
-        <span class="min-w-0 flex-1 wrap-break-word">{{ t.text }}</span>
-        <button
-          (click)="toast.dismiss(t.id)"
-          class="shrink-0 text-muted-foreground hover:text-foreground"
-        >
-          <ng-icon name="mynaX" size="0.9rem" />
-        </button>
-        <!-- auto-dismiss countdown; freezes with the timer while hovered -->
-        <div
-          class="toast-countdown absolute inset-x-0 bottom-0 h-0.5 origin-left"
-          [class.bg-destructive]="t.kind === 'error'"
-          [class.bg-success]="t.kind === 'success'"
-          [class.bg-primary]="t.kind === 'info'"
-          [style.animation-duration.ms]="t.ttlMs"
-        ></div>
-      </div>
-    }
-  </div>
 </div>

ui/src/app/app.ts

@@ -5,7 +5,6 @@ import { ConnectionManager } from './connection-manager/connection-manager';
 import { ConnectionsService } from './connections.service';
 import { ChmodDialog } from './dialogs/chmod-dialog';
 import { ConfirmDialog } from './dialogs/confirm-dialog';
-import { EditorDialog } from './dialogs/editor-dialog';
 import { OverwriteDialog } from './dialogs/overwrite-dialog';
 import { PromptDialog } from './dialogs/prompt-dialog';
 import { DialogsService } from './dialogs.service';
@@ -16,6 +15,7 @@ import { RpcService } from './rpc.service';
 import { StatusBar } from './status-bar/status-bar';
 import { TabBar } from './tab-bar/tab-bar';
 import { ToastService } from './toast.service';
+import { Toasts } from './toasts/toasts';
 import { TransferBar } from './transfer-bar/transfer-bar';
 import { TransfersService } from './transfers.service';
 
@@ -30,7 +30,7 @@ import { TransfersService } from './transfers.service';
     ConfirmDialog,
     ChmodDialog,
     OverwriteDialog,
-    EditorDialog,
+    Toasts,
     TransferBar,
     ConnectionManager,
   ],
@@ -174,9 +174,4 @@ export class App {
     }
   }
 
-  toastIcon(kind: 'error' | 'info' | 'success'): string {
-    if (kind === 'error') return 'mynaXCircle';
-    if (kind === 'success') return 'mynaCheckCircle';
-    return 'mynaCheck';
-  }
 }

ui/src/app/dialogs.service.ts

@@ -1,6 +1,5 @@
 import { Injectable, signal } from '@angular/core';
 import type { FileEntry } from '@shared/types';
-import type { PanelState } from './panels.service';
 
 export type OverwriteChoice = 'overwrite' | 'skip' | 'overwriteAll' | 'skipAll' | 'cancel';
 
@@ -34,22 +33,12 @@ export interface ChmodRequest {
   onConfirm: (mode: number) => void;
 }
 
-export interface EditorRequest {
-  sessionId: string;
-  path: string;
-  name: string;
-  sessionTitle: string;
-  content: string;
-  panel: PanelState; // refreshed after save
-}
-
 @Injectable({ providedIn: 'root' })
 export class DialogsService {
   readonly prompt = signal<PromptRequest | null>(null);
   readonly confirm = signal<ConfirmRequest | null>(null);
   readonly chmod = signal<ChmodRequest | null>(null);
   readonly overwrite = signal<OverwriteRequest | null>(null);
-  readonly editor = signal<EditorRequest | null>(null);
   readonly manager = signal(false);
 
   /** Ask what to do about one name collision; resolves with the user's choice. */

ui/src/app/dialogs/editor-dialog.ts

@@ -1,158 +0,0 @@
-import {
-  Component,
-  ElementRef,
-  afterNextRender,
-  inject,
-  input,
-  signal,
-  viewChild,
-} from '@angular/core';
-import { NgIcon } from '@ng-icons/core';
-import { DialogsService, type EditorRequest } from '../dialogs.service';
-import { PanelsService } from '../panels.service';
-import { RpcService } from '../rpc.service';
-import { ToastService } from '../toast.service';
-
-@Component({
-  selector: 'app-editor-dialog',
-  imports: [NgIcon],
-  template: `
-    <div class="fixed inset-0 z-40 grid place-items-center bg-black/40">
-      <div
-        class="flex h-[80vh] w-[85vw] max-w-5xl flex-col rounded-lg border border-border bg-card text-card-foreground shadow-xl"
-        (keydown)="onKeydown($event)"
-      >
-        <div class="flex items-center gap-2 border-b border-border px-4 py-2.5">
-          <ng-icon name="mynaFileText" size="0.95rem" class="shrink-0 text-muted-foreground" />
-          <h2 class="min-w-0 truncate font-mono text-sm font-semibold">
-            {{ request().name }}{{ dirty() ? ' •' : '' }}
-          </h2>
-          <span class="shrink-0 text-[11px] text-muted-foreground">
-            {{ request().sessionTitle }}
-          </span>
-          <div class="flex-1"></div>
-          <button
-            (click)="close()"
-            class="rounded p-1 text-muted-foreground hover:bg-accent hover:text-foreground"
-          >
-            <ng-icon name="mynaX" size="1rem" />
-          </button>
-        </div>
-
-        <textarea
-          #box
-          [value]="text()"
-          (input)="onInput($any($event.target).value)"
-          spellcheck="false"
-          class="min-h-0 flex-1 resize-none bg-transparent p-4 font-mono text-xs leading-relaxed outline-none"
-        ></textarea>
-
-        <div class="flex items-center gap-2 border-t border-border px-4 py-2.5">
-          <span class="text-[11px] text-muted-foreground">⌘S saves · Esc closes</span>
-          <div class="flex-1"></div>
-          <button
-            (click)="close()"
-            class="rounded-md px-3 py-1.5 text-xs font-medium hover:bg-accent"
-          >
-            Cancel
-          </button>
-          <button
-            (click)="save()"
-            [disabled]="saving() || !dirty()"
-            class="flex items-center gap-1.5 rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
-          >
-            @if (saving()) {
-              <ng-icon name="mynaSpinner" size="0.85rem" class="animate-spin" />
-            }
-            Save
-          </button>
-        </div>
-      </div>
-    </div>
-  `,
-})
-export class EditorDialog {
-  readonly request = input.required<EditorRequest>();
-
-  readonly text = signal('');
-  readonly dirty = signal(false);
-  readonly saving = signal(false);
-
-  private readonly box = viewChild.required<ElementRef<HTMLTextAreaElement>>('box');
-  private readonly dialogs = inject(DialogsService);
-  private readonly panels = inject(PanelsService);
-  private readonly rpc = inject(RpcService);
-  private readonly toast = inject(ToastService);
-
-  constructor() {
-    afterNextRender(() => {
-      this.text.set(this.request().content);
-      this.box().nativeElement.focus();
-    });
-  }
-
-  onInput(value: string): void {
-    this.text.set(value);
-    this.dirty.set(value !== this.request().content);
-  }
-
-  onKeydown(event: KeyboardEvent): void {
-    if ((event.metaKey || event.ctrlKey) && event.key.toLowerCase() === 's') {
-      event.preventDefault();
-      void this.save();
-    } else if (event.key === 'Escape') {
-      event.preventDefault();
-      this.close();
-    } else if (event.key === 'Tab' && event.target === this.box().nativeElement) {
-      // keep Tab as an input character inside the editor
-      event.preventDefault();
-      const el = this.box().nativeElement;
-      const { selectionStart, selectionEnd, value } = el;
-      el.value = `${value.slice(0, selectionStart)}\t${value.slice(selectionEnd)}`;
-      el.selectionStart = el.selectionEnd = selectionStart + 1;
-      this.onInput(el.value);
-    }
-  }
-
-  async save(): Promise<void> {
-    const req = this.request();
-    if (!this.dirty() || this.saving()) return;
-    this.saving.set(true);
-    try {
-      const res = await this.rpc.request.writeFile({
-        sessionId: req.sessionId,
-        path: req.path,
-        content: this.text(),
-      });
-      if (!res.ok) {
-        this.toast.error(res.error);
-        return;
-      }
-      this.toast.success(`Saved ${req.name}`);
-      req.content = this.text();
-      this.dirty.set(false);
-      void req.panel.refresh();
-    } finally {
-      this.saving.set(false);
-    }
-  }
-
-  close(): void {
-    if (this.dirty()) {
-      this.dialogs.confirm.set({
-        title: 'Discard changes?',
-        body: `"${this.request().name}" has unsaved changes.`,
-        confirmLabel: 'Discard',
-        destructive: true,
-        onConfirm: () => this.forceClose(),
-      });
-      return;
-    }
-    this.forceClose();
-  }
-
-  private forceClose(): void {
-    this.dialogs.editor.set(null);
-    this.panels.refocus();
-  }
-}

ui/src/app/editor-window/editor-window.html

@@ -0,0 +1,210 @@
+<div class="flex h-screen flex-col bg-background text-foreground">
+  @if (!ctx) {
+    <div class="flex flex-1 items-center justify-center">
+      <div class="max-w-sm rounded-lg border border-border bg-card p-6 text-center shadow-sm">
+        <ng-icon name="mynaXCircle" size="1.5rem" class="text-destructive" />
+        <p class="mt-2 text-sm font-medium">No file to edit</p>
+        <p class="mt-1 text-xs text-muted-foreground">
+          This window was opened without an editor context. Launch files from the app.
+        </p>
+      </div>
+    </div>
+  } @else {
+    <!-- header: on macOS this row IS the titlebar (hiddenInset + drag region),
+         elsewhere the native titlebar sits above and this is a compact strip -->
+    <header
+      class="flex shrink-0 items-center gap-2 border-b border-border pr-2"
+      [class.h-10]="isMacChrome"
+      [class.pl-24]="isMacChrome"
+      [class.electrobun-webkit-app-region-drag]="isMacChrome"
+      [class.h-9]="!isMacChrome"
+      [class.pl-3]="!isMacChrome"
+    >
+      <ng-icon name="mynaFileText" size="0.95rem" class="shrink-0 text-muted-foreground" />
+      <h1 class="min-w-0 truncate font-mono text-sm font-semibold">
+        {{ ctx.name }}{{ dirty() ? ' •' : '' }}
+      </h1>
+      <span class="shrink-0 text-[11px] text-muted-foreground">{{ ctx.sessionTitle }}</span>
+      <div class="flex-1"></div>
+      <button
+        (click)="toggleWrap()"
+        title="Wrap long lines — hides line numbers (⌥Z)"
+        class="rounded-md px-2 py-1 text-[11px] electrobun-webkit-app-region-no-drag hover:bg-accent"
+        [class.bg-accent]="wrap()"
+        [class.text-foreground]="wrap()"
+        [class.text-muted-foreground]="!wrap()"
+      >
+        Wrap
+      </button>
+      <button
+        (click)="openFind()"
+        title="Find (⌘F)"
+        class="grid size-6 place-items-center rounded-md text-muted-foreground electrobun-webkit-app-region-no-drag hover:bg-accent hover:text-foreground"
+      >
+        <ng-icon name="mynaSearch" size="0.85rem" />
+      </button>
+    </header>
+
+    @if (findOpen()) {
+      <div class="flex shrink-0 items-center gap-2 border-b border-border px-3 py-1.5">
+        <ng-icon name="mynaSearch" size="0.85rem" class="shrink-0 text-muted-foreground" />
+        <input
+          #findBox
+          [value]="findQuery()"
+          (input)="onFindInput($any($event.target).value)"
+          (keydown)="onFindKeydown($event)"
+          placeholder="Find in file"
+          spellcheck="false"
+          class="h-6 w-56 rounded-md border border-input bg-transparent px-2 text-xs outline-none focus:ring-2 focus:ring-ring"
+        />
+        <span
+          class="text-[11px] tabular-nums"
+          [class.text-destructive]="findQuery() && !matches().length"
+          [class.text-muted-foreground]="!findQuery() || matches().length"
+        >
+          {{ countLabel() }}
+        </span>
+        <button
+          (click)="findStep(-1)"
+          title="Previous match (⇧↵)"
+          class="grid size-5 place-items-center rounded text-muted-foreground hover:bg-accent hover:text-foreground"
+        >
+          <ng-icon name="mynaChevronUp" size="0.8rem" />
+        </button>
+        <button
+          (click)="findStep(1)"
+          title="Next match (↵)"
+          class="grid size-5 place-items-center rounded text-muted-foreground hover:bg-accent hover:text-foreground"
+        >
+          <ng-icon name="mynaChevronDown" size="0.8rem" />
+        </button>
+        <div class="flex-1"></div>
+        <button
+          (click)="closeFind()"
+          title="Close (Esc)"
+          class="grid size-5 place-items-center rounded text-muted-foreground hover:bg-accent hover:text-foreground"
+        >
+          <ng-icon name="mynaX" size="0.8rem" />
+        </button>
+      </div>
+    }
+
+    @if (sessionDead()) {
+      <div
+        class="flex shrink-0 items-center gap-2 border-b border-border bg-destructive/10 px-3 py-1.5 text-[11px] text-destructive"
+      >
+        <ng-icon name="mynaXCircle" size="0.85rem" class="shrink-0" />
+        Disconnected from {{ ctx.sessionTitle }} — saving will fail, but your text is preserved
+        in this window.
+      </div>
+    }
+
+    @if (loading()) {
+      <div class="flex flex-1 items-center justify-center">
+        <ng-icon name="mynaSpinner" size="1.25rem" class="animate-spin text-primary" />
+      </div>
+    } @else if (loadError(); as error) {
+      <div class="flex flex-1 items-center justify-center">
+        <div class="max-w-md rounded-lg border border-border bg-card p-6 text-center shadow-sm">
+          <ng-icon name="mynaXCircle" size="1.5rem" class="text-destructive" />
+          <p class="mt-2 text-sm font-medium">Can't open {{ ctx.name }}</p>
+          <p class="mt-1 text-xs text-muted-foreground">{{ error }}</p>
+          <button
+            (click)="discardAndClose()"
+            class="mt-4 rounded-md border border-border px-3 py-1.5 text-xs font-medium hover:bg-accent"
+          >
+            Close Window
+          </button>
+        </div>
+      </div>
+    } @else {
+      <div class="flex min-h-0 flex-1">
+        <!-- gutter and textarea share font/leading/vertical padding — that's
+             the whole alignment contract; keep the classes in lockstep -->
+        @if (!wrap()) {
+          <div
+            #gutter
+            aria-hidden="true"
+            [style.width.ch]="gutterDigits() + 3"
+            class="shrink-0 overflow-hidden border-r border-border py-4 pr-2 text-right font-mono text-xs leading-relaxed whitespace-pre text-muted-foreground select-none"
+          >{{ gutterText() }}</div>
+        }
+        <textarea
+          #box
+          [value]="text()"
+          (input)="onInput($any($event.target).value)"
+          (scroll)="onScroll()"
+          spellcheck="false"
+          [attr.wrap]="wrap() ? 'soft' : 'off'"
+          class="min-h-0 flex-1 resize-none overflow-auto bg-transparent px-4 py-4 font-mono text-xs leading-relaxed outline-none"
+          [class.whitespace-pre]="!wrap()"
+        ></textarea>
+      </div>
+
+      <footer class="flex shrink-0 items-center gap-2 border-t border-border px-4 py-2">
+        <span class="text-[11px] text-muted-foreground">⌘S save · ⌘F find · ⌘W close</span>
+        <span class="text-[11px] text-muted-foreground">·</span>
+        <span class="text-[11px] tabular-nums text-muted-foreground">
+          {{ lineCount() }} {{ lineCount() === 1 ? 'line' : 'lines' }}
+        </span>
+        <div class="flex-1"></div>
+        <button
+          (click)="requestClose()"
+          class="rounded-md px-3 py-1.5 text-xs font-medium hover:bg-accent"
+        >
+          Close
+        </button>
+        <button
+          (click)="save()"
+          [disabled]="saving() || !dirty()"
+          class="flex items-center gap-1.5 rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
+        >
+          @if (saving()) {
+            <ng-icon name="mynaSpinner" size="0.85rem" class="animate-spin" />
+          }
+          Save
+        </button>
+      </footer>
+    }
+
+    <!-- dirty-close prompt. Component-local on purpose: the shared confirm
+         dialog pulls in PanelsService, which must not boot in this window. -->
+    @if (closePrompt()) {
+      <div class="fixed inset-0 z-40 grid place-items-center bg-black/40" (mousedown)="cancelClose()">
+        <div
+          class="w-96 rounded-lg border border-border bg-card p-4 text-card-foreground shadow-xl"
+          (mousedown)="$event.stopPropagation()"
+        >
+          <h2 class="text-sm font-semibold">Save changes to "{{ ctx.name }}"?</h2>
+          <p class="mt-1.5 text-xs text-muted-foreground">
+            Your changes will be lost if you don't save them.
+          </p>
+          <div class="mt-4 flex items-center gap-2">
+            <button
+              (click)="discardAndClose()"
+              class="rounded-md px-3 py-1.5 text-xs font-medium text-destructive hover:bg-accent"
+            >
+              Don't Save
+            </button>
+            <div class="flex-1"></div>
+            <button
+              (click)="cancelClose()"
+              class="rounded-md px-3 py-1.5 text-xs font-medium hover:bg-accent"
+            >
+              Cancel
+            </button>
+            <button
+              (click)="saveAndClose()"
+              [disabled]="saving()"
+              class="rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
+            >
+              Save
+            </button>
+          </div>
+        </div>
+      </div>
+    }
+  }
+
+  <app-toasts />
+</div>

ui/src/app/editor-window/editor-window.ts

@@ -0,0 +1,336 @@
+import {
+  Component,
+  DOCUMENT,
+  ElementRef,
+  afterNextRender,
+  computed,
+  effect,
+  inject,
+  signal,
+  viewChild,
+} from '@angular/core';
+import { NgIcon } from '@ng-icons/core';
+import { EDITOR_CONTEXT, IS_MAC_CHROME } from '../platform';
+import { RpcService } from '../rpc.service';
+import { SettingsService } from '../settings.service';
+import { ToastService } from '../toast.service';
+import { Toasts } from '../toasts/toasts';
+
+/** Debounce for mirroring the draft to bun (the traffic-light-close safety net). */
+const DRAFT_DEBOUNCE_MS = 400;
+
+/**
+ * Root component of an editor window (window.__APP_MODE === 'editor').
+ *
+ * Deliberately injects only Rpc/Toast/Settings: main-window root services
+ * (PanelsService, ConnectionsService, TransfersService — and the dialogs that
+ * inject them) have constructor side effects like creating workspaces and
+ * loading connections that must not run here.
+ */
+@Component({
+  selector: 'app-root',
+  imports: [NgIcon, Toasts],
+  templateUrl: './editor-window.html',
+  host: { '(window:keydown)': 'onKeydown($event)', '(window:blur)': 'flushDraft()' },
+})
+export class EditorWindow {
+  readonly ctx = EDITOR_CONTEXT;
+  readonly isMacChrome = IS_MAC_CHROME;
+
+  readonly loading = signal(true);
+  readonly loadError = signal<string | null>(null);
+  readonly text = signal('');
+  readonly savedContent = signal('');
+  readonly dirty = computed(() => this.text() !== this.savedContent());
+  readonly saving = signal(false);
+  readonly closePrompt = signal(false);
+  readonly sessionDead = signal(false);
+  /** Soft-wrap long lines. Hides the gutter: correct wrapped line numbers
+   *  would need per-edit height measurement — not worth it without an editor lib. */
+  readonly wrap = signal(false);
+  readonly findOpen = signal(false);
+  readonly findQuery = signal('');
+  readonly activeMatch = signal(0);
+
+  /** Line count without allocating a split array on every keystroke. */
+  readonly lineCount = computed(() => {
+    const t = this.text();
+    let n = 1;
+    let i = -1;
+    while ((i = t.indexOf('\n', i + 1)) !== -1) n++;
+    return n;
+  });
+  readonly gutterText = computed(() =>
+    Array.from({ length: this.lineCount() }, (_, i) => i + 1).join('\n'),
+  );
+  readonly gutterDigits = computed(() => String(this.lineCount()).length);
+
+  /** Case-insensitive match start offsets for the find query. */
+  readonly matches = computed(() => {
+    const query = this.findQuery().toLowerCase();
+    if (!query) return [];
+    const hay = this.text().toLowerCase();
+    const out: number[] = [];
+    let i = hay.indexOf(query);
+    while (i !== -1) {
+      out.push(i);
+      i = hay.indexOf(query, i + query.length);
+    }
+    return out;
+  });
+  readonly countLabel = computed(() =>
+    this.matches().length ? `${this.activeMatch() + 1}/${this.matches().length}` : '0/0',
+  );
+
+  private readonly box = viewChild<ElementRef<HTMLTextAreaElement>>('box');
+  private readonly gutter = viewChild<ElementRef<HTMLElement>>('gutter');
+  private readonly findBox = viewChild<ElementRef<HTMLInputElement>>('findBox');
+  private cachedCharWidth = 0;
+  private readonly rpc = inject(RpcService);
+  private readonly toast = inject(ToastService);
+  private readonly document = inject(DOCUMENT);
+  // injected for its side effects: fetches settings and applies theme/accent/
+  // text-size data attributes to this window's document root
+  private readonly settings = inject(SettingsService);
+
+  private draftTimer: ReturnType<typeof setTimeout> | null = null;
+  private lastSentDirty = false;
+
+  constructor() {
+    const ctx = this.ctx;
+    if (!ctx) return; // opened outside the app (plain browser) — error card renders
+
+    const baseTitle = `${ctx.name} — ${ctx.sessionTitle}`;
+    effect(() => {
+      this.document.title = `${this.dirty() ? '• ' : ''}${baseTitle}`;
+    });
+
+    this.rpc.onEditorCloseRequest(() => this.requestClose());
+    this.rpc.onSessionClosed((event) => {
+      if (event.sessionId === ctx.sessionId) this.sessionDead.set(true);
+    });
+
+    afterNextRender(() => void this.load(ctx.sessionId, ctx.path));
+  }
+
+  private async load(sessionId: string, path: string): Promise<void> {
+    const res = await this.rpc.request.readFile({ sessionId, path });
+    if (!res.ok) {
+      this.loadError.set(res.error);
+      this.loading.set(false);
+      return;
+    }
+    this.savedContent.set(res.content);
+    this.text.set(res.content);
+    this.loading.set(false);
+    queueMicrotask(() => this.box()?.nativeElement.focus());
+  }
+
+  onInput(value: string): void {
+    this.text.set(value);
+    this.scheduleDraft();
+  }
+
+  /** Keep the line-number gutter locked to the textarea's scroll position. */
+  onScroll(): void {
+    const gutter = this.gutter()?.nativeElement;
+    if (gutter) gutter.scrollTop = this.box()!.nativeElement.scrollTop;
+  }
+
+  toggleWrap(): void {
+    this.wrap.update((w) => !w);
+    queueMicrotask(() => this.onScroll());
+  }
+
+  // ---- find ----
+
+  openFind(): void {
+    const el = this.box()?.nativeElement;
+    // prefill from the current selection when it's a sane single-line snippet
+    if (el && el.selectionStart !== el.selectionEnd) {
+      const selected = el.value.slice(el.selectionStart, el.selectionEnd);
+      if (selected.length < 200 && !selected.includes('\n')) this.findQuery.set(selected);
+    }
+    this.findOpen.set(true);
+    this.activeMatch.set(0);
+    queueMicrotask(() => {
+      const input = this.findBox()?.nativeElement;
+      input?.focus();
+      input?.select();
+    });
+  }
+
+  closeFind(): void {
+    this.findOpen.set(false);
+    // selection was left on the match — the caret lands there
+    this.box()?.nativeElement.focus();
+  }
+
+  onFindInput(value: string): void {
+    this.findQuery.set(value);
+    const list = this.matches();
+    if (!list.length) return;
+    // jump to the first match at/after the caret, else wrap to the first
+    const from = this.box()?.nativeElement.selectionStart ?? 0;
+    const at = list.findIndex((start) => start >= from);
+    this.goTo(at >= 0 ? at : 0);
+  }
+
+  findStep(delta: 1 | -1): void {
+    const count = this.matches().length;
+    if (!count) return;
+    this.goTo((this.activeMatch() + delta + count) % count);
+  }
+
+  onFindKeydown(event: KeyboardEvent): void {
+    if (event.key === 'Enter') {
+      event.preventDefault();
+      this.findStep(event.shiftKey ? -1 : 1);
+    } else if (event.key === 'Escape') {
+      event.preventDefault();
+      event.stopPropagation();
+      this.closeFind();
+    }
+  }
+
+  /** Select match `index` and scroll it into the middle of the viewport. */
+  private goTo(index: number): void {
+    const el = this.box()?.nativeElement;
+    const start = this.matches()[index];
+    if (!el || start === undefined) return;
+    this.activeMatch.set(index);
+    el.setSelectionRange(start, start + this.findQuery().length);
+
+    const text = this.text();
+    const lineHeight = parseFloat(getComputedStyle(el).lineHeight) || 20;
+    let line = 0;
+    let i = text.indexOf('\n');
+    while (i !== -1 && i < start) {
+      line++;
+      i = text.indexOf('\n', i + 1);
+    }
+    el.scrollTop = Math.max(0, line * lineHeight - el.clientHeight / 2);
+    if (!this.wrap()) {
+      const column = start - (text.lastIndexOf('\n', start - 1) + 1);
+      el.scrollLeft = Math.max(0, column * this.charWidth(el) - el.clientWidth / 2);
+    }
+    this.onScroll();
+  }
+
+  /** Monospace advance width, measured once per window. */
+  private charWidth(el: HTMLTextAreaElement): number {
+    if (!this.cachedCharWidth) {
+      const canvas = this.document.createElement('canvas').getContext('2d')!;
+      canvas.font = getComputedStyle(el).font;
+      this.cachedCharWidth = canvas.measureText('0').width || 7;
+    }
+    return this.cachedCharWidth;
+  }
+
+  // ---- draft mirror: bun holds the latest content for the native-close prompt ----
+
+  private scheduleDraft(): void {
+    if (this.dirty() !== this.lastSentDirty) {
+      // dirty flag flipped — tell bun immediately so the native title updates
+      this.flushDraft();
+      return;
+    }
+    if (this.draftTimer) clearTimeout(this.draftTimer);
+    this.draftTimer = setTimeout(() => this.flushDraft(), DRAFT_DEBOUNCE_MS);
+  }
+
+  flushDraft(): void {
+    if (!this.ctx || this.loading()) return;
+    if (this.draftTimer) {
+      clearTimeout(this.draftTimer);
+      this.draftTimer = null;
+    }
+    this.lastSentDirty = this.dirty();
+    this.rpc.send.editorState({ dirty: this.dirty(), content: this.text() });
+  }
+
+  // ---- save / close ----
+
+  async save(): Promise<boolean> {
+    if (!this.dirty() || this.saving()) return true;
+    const content = this.text();
+    this.saving.set(true);
+    try {
+      const res = await this.rpc.request.editorSave({ content });
+      if (!res.ok) {
+        this.toast.error(res.error);
+        return false;
+      }
+      this.savedContent.set(content);
+      this.lastSentDirty = false; // bun record already cleaned by the handler
+      this.toast.success(`Saved ${this.ctx!.name}`);
+      return true;
+    } finally {
+      this.saving.set(false);
+    }
+  }
+
+  /** ⌘W / Close button / bun's editorCloseRequest: prompt if dirty, else close. */
+  requestClose(): void {
+    if (this.dirty()) {
+      this.closePrompt.set(true);
+    } else {
+      void this.rpc.request.editorClose({});
+    }
+  }
+
+  async saveAndClose(): Promise<void> {
+    if (await this.save()) void this.rpc.request.editorClose({});
+  }
+
+  discardAndClose(): void {
+    void this.rpc.request.editorClose({});
+  }
+
+  cancelClose(): void {
+    this.closePrompt.set(false);
+    queueMicrotask(() => this.box()?.nativeElement.focus());
+  }
+
+  // ---- keyboard ----
+
+  onKeydown(event: KeyboardEvent): void {
+    const mod = event.metaKey || event.ctrlKey;
+    if (mod && event.key.toLowerCase() === 's') {
+      event.preventDefault();
+      void this.save();
+    } else if (mod && event.key.toLowerCase() === 'f') {
+      event.preventDefault();
+      this.openFind();
+    } else if (mod && event.key.toLowerCase() === 'w') {
+      // reaches us on Windows/Linux; on macOS the app menu intercepts ⌘W and
+      // bun routes it back as editorCloseRequest
+      event.preventDefault();
+      this.requestClose();
+    } else if (event.altKey && event.code === 'KeyZ') {
+      event.preventDefault();
+      this.toggleWrap();
+    } else if (event.key === 'Escape' && this.closePrompt()) {
+      event.preventDefault();
+      this.cancelClose();
+    } else if (event.key === 'Escape' && this.findOpen()) {
+      event.preventDefault();
+      this.closeFind();
+    } else if (event.key === 'Tab' && event.target === this.box()?.nativeElement) {
+      // keep Tab as an input character inside the editor
+      event.preventDefault();
+      this.insertTab();
+    }
+  }
+
+  private insertTab(): void {
+    const el = this.box()!.nativeElement;
+    // execCommand keeps the native undo stack intact where supported
+    if (!this.document.execCommand('insertText', false, '\t')) {
+      const { selectionStart, selectionEnd, value } = el;
+      el.value = `${value.slice(0, selectionStart)}\t${value.slice(selectionEnd)}`;
+      el.selectionStart = el.selectionEnd = selectionStart + 1;
+    }
+    this.onInput(el.value);
+  }
+}

ui/src/app/file-actions.service.ts

@@ -105,22 +105,14 @@ export class FileActionsService {
       return;
     }
 
-    const res = await this.rpc.request.readFile({
+    // built-in editor: its own native window (reads the file itself)
-      sessionId: panel.sessionId(),
+    const res = await this.rpc.request.openEditor({
-      path: entry.path,
-    });
-    if (!res.ok) {
-      this.toast.error(res.error);
-      return;
-    }
-    this.dialogs.editor.set({
       sessionId: panel.sessionId(),
       path: entry.path,
       name: entry.name,
       sessionTitle: panel.title(),
-      content: res.content,
-      panel,
     });
+    if (!res.ok) this.toast.error(res.error);
   }
 
   rename(panel: PanelState): void {

ui/src/app/icons.ts

@@ -11,6 +11,7 @@ import {
   mynaCheckCircle,
   mynaChevronDown,
   mynaChevronRight,
+  mynaChevronUp,
   mynaCode,
   mynaCog,
   mynaDots,
@@ -46,6 +47,7 @@ export const APP_ICONS = {
   mynaCheckCircle,
   mynaChevronDown,
   mynaChevronRight,
+  mynaChevronUp,
   mynaCode,
   mynaCog,
   mynaDots,

ui/src/app/panels.service.ts

@@ -223,6 +223,13 @@ export class PanelsService {
         }
       }
     });
+
+    // an editor window saved a file — refresh panels showing that directory
+    this.rpc.onPathRefresh(({ sessionId, dir }) => {
+      for (const panel of this.allPanels()) {
+        if (panel.sessionId() === sessionId && panel.cwd() === dir) void panel.refresh();
+      }
+    });
   }
 
   // ---- panels of the active workspace ----

ui/src/app/platform.ts

@@ -1,12 +1,25 @@
-// Injected by the bun process via BrowserWindow preload before any page script.
+// Injected by the bun process via BrowserWindow preload (src/bun/windows.ts
-// Brand-neutral name so rebrands never touch this file.
+// buildPreload) before any page script. Brand-neutral names so rebrands never
+// touch this file.
+import type { EditorOpenContext } from '@shared/rpc';
+
 declare global {
   interface Window {
     __APP_PLATFORM?: string;
+    /** Which root component this window boots: the full app or one editor. */
+    __APP_MODE?: 'main' | 'editor';
+    /** Window-kind specific context (EditorOpenContext for editor windows). */
+    __APP_CTX?: unknown;
   }
 }
 
 export const PLATFORM = typeof window !== 'undefined' ? (window.__APP_PLATFORM ?? '') : '';
 
-/** True when the window uses macOS hiddenInset chrome (tab bar fused with titlebar). */
+/** True when the window uses macOS hiddenInset chrome (header fused with titlebar). */
 export const IS_MAC_CHROME = PLATFORM === 'darwin';
+
+export const APP_MODE: 'main' | 'editor' =
+  typeof window !== 'undefined' ? (window.__APP_MODE ?? 'main') : 'main';
+
+export const EDITOR_CONTEXT =
+  typeof window !== 'undefined' ? (window.__APP_CTX as EditorOpenContext | undefined) : undefined;

ui/src/app/rpc.service.ts

@@ -1,7 +1,7 @@
 import { Injectable } from '@angular/core';
 import { Electroview } from 'electrobun/view';
 import type { AppRPC } from '@shared/rpc';
-import type { TransferSnapshot } from '@shared/types';
+import type { AppSettings, TransferSnapshot } from '@shared/types';
 
 // Matches MAX_REQUEST_TIME_MS on the bun side — SFTP ops can be slow.
 const MAX_REQUEST_TIME_MS = 10 * 60_000;
@@ -19,6 +19,9 @@ export class RpcService {
   private transferListeners = new Set<(s: TransferSnapshot) => void>();
   private closedListeners = new Set<(e: SessionClosedEvent) => void>();
   private menuListeners = new Set<(action: string) => void>();
+  private settingsListeners = new Set<(settings: AppSettings) => void>();
+  private pathRefreshListeners = new Set<(e: { sessionId: string; dir: string }) => void>();
+  private editorCloseListeners = new Set<() => void>();
 
   private rpc: ReturnType<typeof Electroview.defineRPC<AppRPC>> | undefined;
   private ready: Promise<void> = Promise.resolve();
@@ -40,6 +43,15 @@ export class RpcService {
           menuAction: ({ action }) => {
             for (const listener of this.menuListeners) listener(action);
           },
+          settingsChanged: ({ settings }) => {
+            for (const listener of this.settingsListeners) listener(settings);
+          },
+          pathRefresh: (event) => {
+            for (const listener of this.pathRefreshListeners) listener(event);
+          },
+          editorCloseRequest: () => {
+            for (const listener of this.editorCloseListeners) listener();
+          },
         },
       },
     });
@@ -68,6 +80,18 @@ export class RpcService {
     this.menuListeners.add(listener);
   }
 
+  onSettingsChanged(listener: (settings: AppSettings) => void): void {
+    this.settingsListeners.add(listener);
+  }
+
+  onPathRefresh(listener: (event: { sessionId: string; dir: string }) => void): void {
+    this.pathRefreshListeners.add(listener);
+  }
+
+  onEditorCloseRequest(listener: () => void): void {
+    this.editorCloseListeners.add(listener);
+  }
+
   /** Typed request proxy: `await rpc.request.listDir({...})`. Waits for the bridge. */
   get request() {
     const rpc = this.rpc;
@@ -87,4 +111,20 @@ export class RpcService {
     });
   }
 
+  /** Fire-and-forget message proxy: `rpc.send.editorState({...})`. Waits for the bridge. */
+  get send() {
+    const rpc = this.rpc;
+    if (!rpc) throw new Error('RPC is only available inside the desktop app');
+    const ready = this.ready;
+    return new Proxy({} as (typeof rpc)['send'], {
+      get:
+        (_target, method: string) =>
+        (payload?: unknown) => {
+          void ready.then(() => {
+            const methods = rpc.send as unknown as Record<string, (p?: unknown) => void>;
+            methods[method](payload);
+          });
+        },
+    });
+  }
 }

ui/src/app/settings.service.ts

@@ -32,23 +32,28 @@ export class SettingsService {
     this.applyAccent();
     if (!this.rpc.available) return;
     void this.rpc.request.getSettings({}).then((res) => {
-      if (!res.ok) return;
+      if (res.ok) this.applyAll(res.settings);
-      this.theme.set(res.settings.theme);
-      this.darkTone.set(res.settings.darkTone);
-      this.accent.set(res.settings.accent);
-      this.iconColors.set(res.settings.iconColors);
-      this.speedUnit.set(res.settings.speedUnit);
-      this.textSize.set(res.settings.textSize);
-      this.transferMode.set(res.settings.transferMode);
-      this.transferConcurrency.set(res.settings.transferConcurrency);
-      this.autoClearCompleted.set(res.settings.autoClearCompleted);
-      this.editor.set(res.settings.editor);
-      this.editorApp.set(res.settings.editorApp);
-      this.applyTheme();
-      this.applyDarkTone();
-      this.applyAccent();
-      this.applyTextSize();
     });
+    // editor windows: follow settings the main window saves, live
+    this.rpc.onSettingsChanged((settings) => this.applyAll(settings));
+  }
+
+  private applyAll(settings: AppSettings): void {
+    this.theme.set(settings.theme);
+    this.darkTone.set(settings.darkTone);
+    this.accent.set(settings.accent);
+    this.iconColors.set(settings.iconColors);
+    this.speedUnit.set(settings.speedUnit);
+    this.textSize.set(settings.textSize);
+    this.transferMode.set(settings.transferMode);
+    this.transferConcurrency.set(settings.transferConcurrency);
+    this.autoClearCompleted.set(settings.autoClearCompleted);
+    this.editor.set(settings.editor);
+    this.editorApp.set(settings.editorApp);
+    this.applyTheme();
+    this.applyDarkTone();
+    this.applyAccent();
+    this.applyTextSize();
   }
 
   setTheme(theme: AppSettings['theme']): void {

ui/src/app/toasts/toasts.ts

@@ -0,0 +1,50 @@
+import { Component, inject } from '@angular/core';
+import { NgIcon } from '@ng-icons/core';
+import { ToastService } from '../toast.service';
+
+/** Toast stack overlay; shared by the main window and editor windows. */
+@Component({
+  selector: 'app-toasts',
+  imports: [NgIcon],
+  template: `
+    <div class="pointer-events-none fixed right-3 bottom-8 z-50 flex w-80 flex-col gap-2">
+      @for (t of toast.toasts(); track t.id) {
+        <div
+          (mouseenter)="toast.pause(t.id)"
+          (mouseleave)="toast.resume(t.id)"
+          class="group pointer-events-auto relative flex items-start gap-2 overflow-hidden rounded-lg border border-border bg-card p-3 text-xs text-card-foreground shadow-lg"
+        >
+          <ng-icon
+            [name]="toastIcon(t.kind)"
+            size="1rem"
+            [class]="t.kind === 'error' ? 'shrink-0 text-destructive' : 'shrink-0 text-success'"
+          />
+          <span class="min-w-0 flex-1 wrap-break-word">{{ t.text }}</span>
+          <button
+            (click)="toast.dismiss(t.id)"
+            class="shrink-0 text-muted-foreground hover:text-foreground"
+          >
+            <ng-icon name="mynaX" size="0.9rem" />
+          </button>
+          <!-- auto-dismiss countdown; freezes with the timer while hovered -->
+          <div
+            class="toast-countdown absolute inset-x-0 bottom-0 h-0.5 origin-left"
+            [class.bg-destructive]="t.kind === 'error'"
+            [class.bg-success]="t.kind === 'success'"
+            [class.bg-primary]="t.kind === 'info'"
+            [style.animation-duration.ms]="t.ttlMs"
+          ></div>
+        </div>
+      }
+    </div>
+  `,
+})
+export class Toasts {
+  readonly toast = inject(ToastService);
+
+  toastIcon(kind: 'error' | 'info' | 'success'): string {
+    if (kind === 'error') return 'mynaXCircle';
+    if (kind === 'success') return 'mynaCheckCircle';
+    return 'mynaCheck';
+  }
+}

ui/src/main.ts

@@ -1,5 +1,9 @@
 import { bootstrapApplication } from '@angular/platform-browser';
 import { appConfig } from './app/app.config';
 import { App } from './app/app';
+import { EditorWindow } from './app/editor-window/editor-window';
+import { APP_MODE } from './app/platform';
 
-bootstrapApplication(App, appConfig).catch((err) => console.error(err));
+// One bundle, two window kinds: the preload global picks the root component.
+const root = APP_MODE === 'editor' ? EditorWindow : App;
+bootstrapApplication(root, appConfig).catch((err) => console.error(err));