Remove the Windows 7 (7.css) skin

The win7 skin is dropped. Everything else the branch built stays: Linux
support and the HTML context menus, the workspace-tab menu, the continuous
interface scale (rem everywhere, stepper, Ctrl/Cmd +/-/0) and the core/
service layer. The modern tree already carried all of them, and nothing
outside skins/7like/ imported the win7 tree except main.ts and styles.css.

Removed: the skins/7like/ tree (5.1k lines, fonts), the 7.css dependency,
the skin setting and its options row + strings in all 7 locales, the
frameless-window plumbing (window-control RPCs, windowState push,
trackMaximizeState, the synthesized resize grip and its postinstall
watchdog), the session-skin pinning in buildPreload/chromeOptions, the
skin/skinfix cascade layers, and the win7-only probes and screenshot
harness (the harness cannot render the modern tree: plain Firefox has no
RPC bridge). chromeOptions() stays as the one shared frame decision.

Fixed on the way out:
- index.html's per-theme pre-paint background is restored. The branch had
  replaced it with a win7-only transparent rule, so modern dark windows had
  silently lost one of the three flash guards.
- editor-windows.ts wrote its window-key separator as a literal NUL byte,
  which made git and grep treat the file as binary; it is `\0` now (same
  string at runtime).

No settings migration: a stale "skin" key is carried harmlessly by the
store's spread-merge and dropped on the next save.

UI bundle: 616.7 kB -> 405.4 kB, back under the 500 kB budget.

Docs: architecture, gotchas and platform-notes lose the win7 material but
keep what stays true (construction-time preloads/frames, drag regions
ignoring preventDefault, electrobun's missing resize/maximize primitives);
flash-prevention, dev-URL and Bun-panic notes move back under Electrobun;
stale context-menu/tab-bar links fixed; README documents the scale keys.

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

src/shared/i18n/de.ts

@@ -33,12 +33,6 @@ export const de = {
 		title: "Optionen",
 		language: "Sprache",
 		system: "System",
-		skin: {
-			label: "Optik",
-			modern: "Modern",
-			win7: "Windows 7",
-			restartHint: "Wird beim nächsten Start von miniSCP übernommen",
-		},
 		theme: { label: "Design", system: "System", light: "Hell", dark: "Dunkel" },
 		tone: { label: "Ton", dark: "Dunkel", darker: "Dunkler" },
 		accent: { label: "Akzent" },

src/shared/i18n/en.ts

@@ -37,12 +37,6 @@ export const en = {
 		title: "Options",
 		language: "Language",
 		system: "System",
-		skin: {
-			label: "Skin",
-			modern: "Modern",
-			win7: "Windows 7",
-			restartHint: "Applies next time you start miniSCP",
-		},
 		theme: { label: "Theme", system: "System", light: "Light", dark: "Dark" },
 		tone: { label: "Tone", dark: "Dark", darker: "Darker" },
 		accent: { label: "Accent" },

src/shared/i18n/es.ts

@@ -33,12 +33,6 @@ export const es = {
 		title: "Opciones",
 		language: "Idioma",
 		system: "Sistema",
-		skin: {
-			label: "Aspecto",
-			modern: "Moderno",
-			win7: "Windows 7",
-			restartHint: "Se aplica la próxima vez que abras miniSCP",
-		},
 		theme: { label: "Tema", system: "Sistema", light: "Claro", dark: "Oscuro" },
 		tone: { label: "Tono", dark: "Oscuro", darker: "Más oscuro" },
 		accent: { label: "Acento" },

src/shared/i18n/eu.ts

@@ -35,12 +35,6 @@ export const eu = {
 		title: "Aukerak",
 		language: "Hizkuntza",
 		system: "Sistema",
-		skin: {
-			label: "Itxura",
-			modern: "Modernoa",
-			win7: "Windows 7",
-			restartHint: "Hurrengoan miniSCP abiaraztean aplikatuko da",
-		},
 		theme: { label: "Gaia", system: "Sistema", light: "Argia", dark: "Iluna" },
 		tone: { label: "Tonua", dark: "Iluna", darker: "Ilunagoa" },
 		accent: { label: "Azentua" },

src/shared/i18n/fr.ts

@@ -33,12 +33,6 @@ export const fr = {
 		title: "Options",
 		language: "Langue",
 		system: "Système",
-		skin: {
-			label: "Apparence",
-			modern: "Moderne",
-			win7: "Windows 7",
-			restartHint: "Prend effet au prochain démarrage de miniSCP",
-		},
 		theme: { label: "Thème", system: "Système", light: "Clair", dark: "Sombre" },
 		tone: { label: "Ton", dark: "Sombre", darker: "Plus sombre" },
 		accent: { label: "Accent" },

src/shared/i18n/ja.ts

@@ -34,12 +34,6 @@ export const ja = {
 		title: "オプション",
 		language: "言語",
 		system: "システム",
-		skin: {
-			label: "外観",
-			modern: "モダン",
-			win7: "Windows 7",
-			restartHint: "次回 miniSCP を起動したときに適用されます",
-		},
 		theme: { label: "テーマ", system: "システム", light: "ライト", dark: "ダーク" },
 		tone: { label: "トーン", dark: "ダーク", darker: "より暗く" },
 		accent: { label: "アクセント" },

src/shared/i18n/zh.ts

@@ -34,12 +34,6 @@ export const zh = {
 		title: "选项",
 		language: "语言",
 		system: "系统",
-		skin: {
-			label: "外观",
-			modern: "现代",
-			win7: "Windows 7",
-			restartHint: "下次启动 miniSCP 时生效",
-		},
 		theme: { label: "主题", system: "系统", light: "浅色", dark: "深色" },
 		tone: { label: "色调", dark: "深色", darker: "更深" },
 		accent: { label: "强调色" },

src/shared/rpc.ts

@@ -128,7 +128,7 @@ export type AppRPC = {
 			// local shell integration
 			/**
 			 * Shell actions the context menu triggers on a LOCAL path. The menu
-			 * itself is HTML (ui/src/app/context-menu.ts) — electrobun's native
+			 * itself is HTML (ui/src/app/core/context-menu.service.ts) — electrobun's native
 			 * context menu is a no-op on Linux — but these three still need the
 			 * bun side's Utils.
 			 */
@@ -154,35 +154,6 @@ export type AppRPC = {
 			managerConnect: { params: { id: string }; response: Result };
 			managerOpenStack: { params: { id: string }; response: Result };
 			managerClose: { params: Record<string, never>; response: Result };
-			// custom window chrome (win7 skin — the window is frameless, so the
-			// webview's title bar owns the controls). Served by every window kind.
-			windowMinimize: { params: Record<string, never>; response: Result };
-			/** Maximize/restore in one call; responds with the resulting state. */
-			windowToggleMaximize: {
-				params: Record<string, never>;
-				response: Result<{ maximized: boolean }>;
-			};
-			windowClose: { params: Record<string, never>; response: Result };
-			/** First paint: the title bar needs the state before any resize fires. */
-			windowIsMaximized: {
-				params: Record<string, never>;
-				response: Result<{ maximized: boolean }>;
-			};
-			/**
-			 * STOPGAP — the two halves of the synthesized resize. A frameless GTK
-			 * window has no resize borders and electrobun exposes no native resize
-			 * gesture, so the webview drags its own handles and moves the frame
-			 * itself. Delete both with the rest of the hack; see the removal
-			 * checklist in ui/src/app/skins/7like/window-resize/window-resize.ts.
-			 */
-			windowGetFrame: {
-				params: Record<string, never>;
-				response: Result<{ x: number; y: number; width: number; height: number }>;
-			};
-			windowSetFrame: {
-				params: { x: number; y: number; width: number; height: number };
-				response: Result;
-			};
 			// auto-updater (electrobun Updater)
 			/** Main window: re-run the update check on demand (menu item). */
 			checkForUpdate: {
@@ -213,13 +184,6 @@ export type AppRPC = {
 			editorCloseRequest: Record<string, never>;
 			/** bun → main: the modal connection manager opened/closed. */
 			managerState: { open: boolean };
-			/**
-			 * bun → any window: maximize state changed, so the custom title bar can
-			 * swap its maximize/restore glyph. electrobun has no maximize event —
-			 * this is derived from the window's `resize` event (see windows.ts
-			 * trackMaximizeState), which also covers OS-initiated Aero Snap.
-			 */
-			windowState: { maximized: boolean };
 			/** bun → main: the manager window changed the connection store. */
 			connectionsChanged: Record<string, never>;
 			/**

src/shared/types.ts

@@ -78,18 +78,6 @@ export type AccentTone =
 export interface AppSettings {
 	/** UI language; "system" resolves to the OS locale (fallback English). */
 	locale: "system" | SupportedLocale;
-	/**
-	 * Visual skin. "modern" is the shadcn-style look; "win7" swaps in 7.css
-	 * (Windows 7 Aero) and switches the window to custom frameless chrome.
-	 * Each skin is a whole component tree under ui/src/app/skins/ — "modern" is
-	 * shadlike/, "win7" is 7like/ — selected at bootstrap in ui/src/main.ts.
-	 * The value is NOT named after its folder on purpose: it is persisted in
-	 * user settings, and "win7" is also the literal class 7.scoped.css is
-	 * precompiled to require, so neither can be renamed freely.
-	 * Changing this needs a window reopen to take effect on the frame itself —
-	 * the CSS half applies live.
-	 */
-	skin: "modern" | "win7";
 	theme: "system" | "light" | "dark";
 	/** Dark appearance: grey ("dark") or near-black AMOLED ("darker"). */
 	darkTone: "dark" | "darker";
@@ -103,7 +91,7 @@ export interface AppSettings {
 	/**
 	 * Interface scale factor, 0.5–4 in 0.1 steps (shown as 50%–400%). Works by
 	 * setting the root font-size — every size in the UI is rem, so one lever
-	 * scales BOTH skins whole. Replaced the 3-tier `textSize`
+	 * scales the whole UI. Replaced the 3-tier `textSize`
 	 * (compact|default|large); SettingsStore.load migrates old files.
 	 */
 	uiScale: number;
@@ -125,7 +113,6 @@ export interface AppSettings {
 
 export const DEFAULT_SETTINGS: AppSettings = {
 	locale: "system",
-	skin: "modern",
 	theme: "system",
 	darkTone: "dark",
 	accent: "blue",