v1.1: fix transfer freeze, session tabs, per-panel toolbars, status bar

Freeze root cause: TransfersService consumed transferUpdate through an effect
that both read and wrote the jobMap signal — the first progress message spun
the effect into an infinite re-run loop, pegging the webview thread while the
copy completed fine bun-side. Push messages now flow through plain callback
registries on RpcService (also stops signal coalescing from dropping progress
snapshots). Verified live: a 60MB boot-time self-test copy streamed progress
into the running UI and the post-completion panel refreshes arrived.

- Tabs: workspaces (left+right PanelState pair each) in PanelsService; tab bar
  replaces the header; sessions persist in background tabs; Cmd+T/Cmd+W/Ctrl+Tab;
  closing a tab disconnects its sessions; last tab can't close
- Per-panel toolbar (top, icon-only): direction-explicit copy (-> / <-),
  rename, new folder/file, chmod, delete; panel footers removed
- VSCode-style status bar: transfer summary (spinner/percent/queued/failures,
  click to expand the job list) + active panel info; function bar removed
- transfer details list is collapsible, auto-expands on failure

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

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

@@ -2,17 +2,16 @@ import { Injectable, inject } from '@angular/core';
 import type { FileEntry } from '@shared/types';
 import { DialogsService } from './dialogs.service';
 import { joinPath } from './format';
-import { PanelsService, type PanelState } from './panels.service';
+import { type PanelState } from './panels.service';
 import { RpcService } from './rpc.service';
 import { ToastService } from './toast.service';
 
 /**
- * File operations invoked from the function bar / keyboard. They always act on
- * the ACTIVE panel: on the selection if there is one, else on the cursor row.
+ * File operations invoked from a panel's toolbar / keyboard. They act on the
+ * GIVEN panel: on the selection if there is one, else on the cursor row.
  */
 @Injectable({ providedIn: 'root' })
 export class FileActionsService {
-  private readonly panels = inject(PanelsService);
   private readonly rpc = inject(RpcService);
   private readonly toast = inject(ToastService);
   private readonly dialogs = inject(DialogsService);
@@ -25,8 +24,7 @@ export class FileActionsService {
     return atCursor ? [atCursor] : [];
   }
 
-  mkdir(): void {
-    const panel = this.panels.active();
+  mkdir(panel: PanelState): void {
     this.dialogs.prompt.set({
       title: 'New folder',
       placeholder: 'folder name',
@@ -42,8 +40,7 @@ export class FileActionsService {
     });
   }
 
-  createFile(): void {
-    const panel = this.panels.active();
+  createFile(panel: PanelState): void {
     this.dialogs.prompt.set({
       title: 'New file',
       placeholder: 'file name',
@@ -59,8 +56,7 @@ export class FileActionsService {
     });
   }
 
-  rename(): void {
-    const panel = this.panels.active();
+  rename(panel: PanelState): void {
     const entry = panel.sorted()[panel.cursor()];
     if (!entry) return;
     this.dialogs.prompt.set({
@@ -80,8 +76,7 @@ export class FileActionsService {
     });
   }
 
-  delete(): void {
-    const panel = this.panels.active();
+  delete(panel: PanelState): void {
     const targets = this.targets(panel);
     if (!targets.length) return;
     const what =
@@ -102,8 +97,7 @@ export class FileActionsService {
     });
   }
 
-  chmod(): void {
-    const panel = this.panels.active();
+  chmod(panel: PanelState): void {
     const targets = this.targets(panel);
     if (!targets.length) return;
     this.dialogs.chmod.set({