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/download.ts

@@ -23,7 +23,7 @@ import { ensureManagedYtdlp } from './ytdlp'
 import { materializeCookies, hasStoredCookies } from './cookies'
 import { listTemplates } from './templates'
 import { assertHttpUrl } from './url'
-import { isSafeOutputDir } from './validation'
+import { isSafeOutputDir } from './core/validation'
 import {
   buildArgs,
   selectExtraArgs,
@@ -32,7 +32,7 @@ import {
   PROGRESS_MARKER,
   FILEPATH_MARKER,
   DEST_MARKER
-} from './buildArgs'
+} from './core/buildArgs'
 import { cleanError } from './log'
 import { addErrorLog } from './errorlog'
 import {