fix(client): localize the read-aloud interface

Replace the hardcoded English in the TTS and narration components with
message keys, label every icon-only control, and add settings.common.nav.tts,
which the settings sidebar rendered as a raw key.

Stop requiring PODCAST_ENCRYPTION_KEY while APP_FEATURES.podcasts is off, and
skip podcast routes and permissions in the authorization matrix for the same
reason.

Pass the direct-download settle() helper the SETTLE_MS budget the file already
defines: vi.waitFor's one-second default cannot cover six DNS-resolved redirect
hops on a cold CI resolver.

server/test/e2e/authorization-matrix/route-inventory/manifest.json

@@ -1,12 +1,12 @@
 {
-  "totalRoutes": 606,
+  "totalRoutes": 612,
   "byPermission": {
-    "(none)": 259,
+    "(none)": 260,
     "Permission.ManageMetadataConfig": 34,
     "Permission.EmailSend": 30,
     "Permission.LibraryEditMetadata": 35,
     "Permission.BookDockAccess": 17,
-    "Permission.ManageAppSettings": 57,
+    "Permission.ManageAppSettings": 62,
     "Permission.ManageLibraries": 22,
     "Permission.ManageUsers": 13,
     "Permission.ManageEmail": 8,