feat(audit): Batch 25 — project reorg (CC12), leading DI args (CC7), CC10 by-design

CC12: renderer views/ (5 screens + Onboarding + settings cards) +
lib/ (theme/thumb/datetime/id/qualityOptions/useClipboardLink/queueStats);
main core/ (buildArgs/validation/indexerCore/ytdlpPolicy). git mv preserved
history; all src+test imports updated. Build emits view chunks from views/,
344 tests + typecheck green, live probe rendered all screens.
CC7: wc/onProgress is the leading arg everywhere — downloadAppUpdate(wc,url),
indexSource(onProgress,url,signal), indexSourceCancelable(onProgress,url).
CC10: closed by-design — jsonStore backs all records; settings stay in
electron-store for DPAPI secret encryption (a deliberate two-store split).
Also closes the UI24/W4 context-menu cross-reference.

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

src/main/sources.ts

@@ -13,8 +13,8 @@
  */
 
 import type { Source, MediaItem } from '@shared/ipc'
-import { isValidSource, isValidMediaItem } from './validation'
-import { mergeItemsPreservingState } from './indexerCore'
+import { isValidSource, isValidMediaItem } from './core/validation'
+import { mergeItemsPreservingState } from './core/indexerCore'
 import { createJsonStore } from './jsonStore'
 // A generous global cap (MEDIA_ITEMS_MAX, see constants.ts) so a runaway index
 // can't grow the file unbounded; large enough for several big channels. When