Skin is a launch-time choice; stop applying it to a live window

Switching Modern -> Win7 at runtime broke the UI. SettingsService.applySkin
toggled the `.win7` class the moment the setting changed — harmless when there
was one component tree, and a broken window as soon as there were two. The tree
is bootstrapped once from the preload-baked __APP_SKIN, so the live flip painted
7.css onto shadlike markup that has no .window.glass, no .title-bar, no
menu[role=tablist] and no <table> ListView. The CSS landed on a tree that cannot
receive it.

A reload would not have helped, and neither would anything short of a restart:

- The preload is a persistent WebKitUserScript injected at DOCUMENT_START, so
  its string is frozen at webview construction — loadURL() re-runs it with the
  OLD __APP_SKIN. updatePreloadScriptToWebView exists in the FFI but is
  reachable only from electrobun's internal <electrobun-webview> handler.
- titleBarStyle/transparent have no setters; a live window cannot be re-framed.
  win7 -> modern is the dangerous direction — the modern tree draws no title
  bar, so it would land in a frameless transparent window with no way to move,
  minimize or close it.
- Recreating the main window is also out: exitOnLastWindowClosed is true, the
  main rpc is captured by six push closures, the tray captures `win`, and
  listeners cannot be removed.

So: applySkin is deleted outright, from setSkin AND from applyAll — the latter
matters independently, since applyAll runs on the settingsChanged push and was
therefore breaking every open editor and manager window too. Clicking a skin now
only persists it.

Also fixed a second leak found while tracing this: manager-window and
editor-windows build from `currentSettings()`, the LIVE snapshot, so a window
opened after a pending change would boot the new tree and frame while main still
ran the old one. `initSessionSkin` now freezes the skin at startup before any
window exists, and buildPreload/chromeOptions read that pinned value —
chromeOptions loses its parameter so no call site can get it wrong.

The options row shows the saved value as pending (skinPending() compares
settings.skin() against APP_SKIN) with the hint retexted in all 7 locales; it
said "Reopen the window to change its frame", which described the deleted
design.

Verified: tsc + build:ui clean; both skins boot correctly from a persisted
setting (win7 frameless, modern with the native frame). The live flip is now
impossible by construction, which is the check that matters here — the UI bundle
contains no classList write for win7 at all, the only writer is buildPreload,
and sessionSkin has exactly one assignment site.

Not verified: the click itself and the pending hint appearing, which need an
interaction pass — no window automation is available here. Both are present in
the built bundle.

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

src/shared/i18n/de.ts

@@ -37,7 +37,7 @@ export const de = {
 			label: "Optik",
 			modern: "Modern",
 			win7: "Windows 7",
-			restartHint: "Fenster neu öffnen, um den Rahmen zu ändern",
+			restartHint: "Wird beim nächsten Start von miniSCP übernommen",
 		},
 		theme: { label: "Design", system: "System", light: "Hell", dark: "Dunkel" },
 		tone: { label: "Ton", dark: "Dunkel", darker: "Dunkler" },

src/shared/i18n/en.ts

@@ -41,7 +41,7 @@ export const en = {
 			label: "Skin",
 			modern: "Modern",
 			win7: "Windows 7",
-			restartHint: "Reopen the window to change its frame",
+			restartHint: "Applies next time you start miniSCP",
 		},
 		theme: { label: "Theme", system: "System", light: "Light", dark: "Dark" },
 		tone: { label: "Tone", dark: "Dark", darker: "Darker" },

src/shared/i18n/es.ts

@@ -37,7 +37,7 @@ export const es = {
 			label: "Aspecto",
 			modern: "Moderno",
 			win7: "Windows 7",
-			restartHint: "Vuelve a abrir la ventana para cambiar su marco",
+			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" },

src/shared/i18n/eu.ts

@@ -39,7 +39,7 @@ export const eu = {
 			label: "Itxura",
 			modern: "Modernoa",
 			win7: "Windows 7",
-			restartHint: "Ireki leihoa berriro bere markoa aldatzeko",
+			restartHint: "Hurrengoan miniSCP abiaraztean aplikatuko da",
 		},
 		theme: { label: "Gaia", system: "Sistema", light: "Argia", dark: "Iluna" },
 		tone: { label: "Tonua", dark: "Iluna", darker: "Ilunagoa" },

src/shared/i18n/fr.ts

@@ -37,7 +37,7 @@ export const fr = {
 			label: "Apparence",
 			modern: "Moderne",
 			win7: "Windows 7",
-			restartHint: "Rouvrez la fenêtre pour changer son cadre",
+			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" },

src/shared/i18n/ja.ts

@@ -38,7 +38,7 @@ export const ja = {
 			label: "外観",
 			modern: "モダン",
 			win7: "Windows 7",
-			restartHint: "ウィンドウの枠を変更するには開き直してください",
+			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" },

src/shared/i18n/zh.ts

@@ -38,7 +38,7 @@ export const zh = {
 			label: "外观",
 			modern: "现代",
 			win7: "Windows 7",
-			restartHint: "重新打开窗口以更改窗口边框",
+			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" },