refactor(frontend): the flat components/ folder moves into shell/, modules/<page>/ and features/<name>/

A pure move (git mv, history kept): 333 files leave components/, which now holds only the platform
layer (ui/) and the legal pages. The shell is the frame (App, header, nav rail, palette, boot); each
page lives in modules/<page>/ with its rail, store and tests; what several pages share sits in
features/<name>/; the shared-link page is watch/. Domain-free helpers went straight to ui/
(ViewSwitcher, FilterRail, the confirm dialog, the language switcher, the copy rows).

Every relative specifier was rewritten (imports, dynamic imports, vi.mock, new URL), and the
contract tests that scan sources now scan the whole app source, not only components/ — each glob
was counted before and after so none went green over fewer files. The locale-format rule matched
`/src/components/` only, so the move would have taken ~300 files out from under its i18n-singleton
check; it now covers every folder that holds components, with a test per folder.

frontend/src/components/ui/pressableSelectable.contract.test.ts

@@ -10,66 +10,74 @@ import { readSources } from "../../lib/rawSources.testkit";
 // someone decides.
 
 const files = readSources(__dirname, [
-  "../**/*.tsx",
-  "!../**/*.test.*",
-  "!../design-lab/**",
+  "../../**/*.tsx",
+  "!../../**/*.test.*",
+  "!../../design-lab/**",
 ]) as Record<string, string>;
 
 /** file → [how many plain Pressables, why they are not titles]. */
 const PLAIN: Record<string, [number, string]> = {
-  "ApiTokens.tsx": [
+  "modules/settings/ApiTokens.tsx": [
     1,
     "a token kind's tile in the new-token dialog (an option: its text is its label)",
   ],
-  "DownloadTray.tsx": [
+  "features/downloads/DownloadTray.tsx": [
     2,
     "the folded pill (its summary is its label); a failure's reason, which opens its details",
   ],
-  "FileCard.tsx": [1, "a card's picture (named by aria-label; its title is the caption)"],
-  "FilesRail.tsx": [2, "the load-error retry; the New-folder command"],
-  "Home.tsx": [
+  "modules/files/FileCard.tsx": [
+    1,
+    "a card's picture (named by aria-label; its title is the caption)",
+  ],
+  "modules/files/FilesRail.tsx": [2, "the load-error retry; the New-folder command"],
+  "modules/home/Home.tsx": [
     2,
     "the hero's picture and a shelf tile's picture (each named by aria-label; its title sits outside)",
   ],
-  "LanguageSwitcher.tsx": [1, "an option row"],
-  "NavSidebar.tsx": [3, "the account trigger and its menu rows"],
-  "PaletteLauncher.tsx": [2, "launcher controls"],
-  "PlaylistsRail.tsx": [1, "the load-error retry"],
-  "PlexCollectionEditor.tsx": [1, "a checkbox row in a picker"],
-  "PlexInfo.tsx": [1, "the rating filter (a number)"],
-  "PlexPlayerSettings.tsx": [1, "the clock's date-style options"],
-  "PlexPlaylistAdd.tsx": [1, "a checkbox row in a picker"],
-  "PlexPlaylistView.tsx": [1, "a show's poster stack (aria-hidden)"],
-  "PlexSearchBox.tsx": [1, "a listbox option"],
-  "plexCards.tsx": [1, "a card's picture (named by aria-label; its title is the caption)"],
-  "Scheduler.tsx": [1, "the interval editor trigger"],
-  "SettingsPanel.tsx": [1, "a colour swatch"],
-  "SyncStatus.tsx": [1, "the status pill trigger"],
-  "TagManager.tsx": [1, "a suggestion in a picker"],
-  "UploadDialog.tsx": [1, "the drop zone"],
-  "VideoEditor.tsx": [2, "timeline glyphs"],
-  "Welcome.tsx": [1, "a screenshot (zoom)"],
-  "playlistColumns.tsx": [1, "the thumbnail"],
-  "plexDetailUi.tsx": [2, "a switch row and the poster"],
-  "plexViews.tsx": [1, "the rating filter (a number)"],
-  "ui/ActionMenu.tsx": [1, "a menu row"],
-  "ui/BackToTop.tsx": [1, "a control"],
-  "ui/CommandPalette.tsx": [1, "a command row"],
-  "ui/NavRail.tsx": [
+  "components/ui/LanguageSwitcher.tsx": [1, "an option row"],
+  "shell/NavSidebar.tsx": [3, "the account trigger and its menu rows"],
+  "features/header/PaletteLauncher.tsx": [2, "launcher controls"],
+  "modules/playlists/PlaylistsRail.tsx": [1, "the load-error retry"],
+  "modules/plex/PlexCollectionEditor.tsx": [1, "a checkbox row in a picker"],
+  "modules/plex/PlexInfo.tsx": [1, "the rating filter (a number)"],
+  "modules/plex/PlexPlayerSettings.tsx": [1, "the clock's date-style options"],
+  "features/plexCards/PlexPlaylistAdd.tsx": [1, "a checkbox row in a picker"],
+  "modules/plex/PlexPlaylistView.tsx": [1, "a show's poster stack (aria-hidden)"],
+  "modules/plex/PlexSearchBox.tsx": [1, "a listbox option"],
+  "features/plexCards/plexCards.tsx": [
+    1,
+    "a card's picture (named by aria-label; its title is the caption)",
+  ],
+  "modules/scheduler/Scheduler.tsx": [1, "the interval editor trigger"],
+  "modules/settings/SettingsPanel.tsx": [1, "a colour swatch"],
+  "modules/channels/SyncStatus.tsx": [1, "the status pill trigger"],
+  "modules/channels/TagManager.tsx": [1, "a suggestion in a picker"],
+  "modules/files/UploadDialog.tsx": [1, "the drop zone"],
+  "features/player/VideoEditor.tsx": [2, "timeline glyphs"],
+  "shell/Welcome.tsx": [1, "a screenshot (zoom)"],
+  "modules/playlists/playlistColumns.tsx": [1, "the thumbnail"],
+  "modules/plex/plexDetailUi.tsx": [2, "a switch row and the poster"],
+  "modules/plex/plexViews.tsx": [1, "the rating filter (a number)"],
+  "components/ui/ActionMenu.tsx": [1, "a menu row"],
+  "components/ui/BackToTop.tsx": [1, "a control"],
+  "components/ui/CommandPalette.tsx": [1, "a command row"],
+  "components/ui/NavRail.tsx": [
     2,
     "the action rows (About, Sign out) and the group row that opens its panel; a page row is a link",
   ],
-  "ui/PanelGroup.tsx": [2, "a group's collapse toggle and its label"],
-  "ui/SidePanel.tsx": [2, "panel controls"],
-  "ui/tableHeader.tsx": [1, "a column's sort header"],
+  "components/ui/PanelGroup.tsx": [2, "a group's collapse toggle and its label"],
+  "components/ui/SidePanel.tsx": [2, "panel controls"],
+  "components/ui/tableHeader.tsx": [1, "a column's sort header"],
 };
 
 function scan(): { plain: Record<string, number>; selectable: number } {
   const plain: Record<string, number> = {};
   let selectable = 0;
   for (const [path, code] of Object.entries(files)) {
-    // Glob keys are relative to this folder: `./x.tsx` is ui/, `../x.tsx` is components/.
-    const rel = path.startsWith("./") ? `ui/${path.slice(2)}` : path.replace(/^\.\.\//, "");
+    // Glob keys are relative to this folder (`./x.tsx` is ui/); the table keys them from src/.
+    const rel = path.startsWith("./")
+      ? `components/ui/${path.slice(2)}`
+      : path.replace(/^(\.\.\/)+/, "");
     for (const m of code.matchAll(/<Pressable\b/g)) {
       if (/\sselectable\b(?!=)/.test(openingTag(code, m.index))) selectable++;
       else plain[rel] = (plain[rel] ?? 0) + 1;