feat(books): add read-aloud delivery policies and preserve sync

Add original and text-only EPUB delivery choices across Kobo, KOReader,
OPDS, web downloads and email while keeping source files unchanged.
Persist server defaults, device overrides and captured artifact identities
so retries and guided replacement retain the selected rendition.

Preserve saved progress across first opens, replacement resets and stale
updates, and project annotations against the copy delivered to each device.
Handle XML resource references, large inodes, retry backoff and background
worker state correctly. Consolidate the schema changes into one migration
and retain released-client request and response compatibility.

Verify with the full server and client checks, delivery and sync HTTP suites,
independent code reviews, and live KOReader download/settings/reader proof.

Fixes #1496
Closes #1603
Closes #1714
Fixes #1723
Ref #1633
Ref #1508
Ref #1621
Ref #1136

client/src/locales/en.json

@@ -5174,7 +5174,11 @@
       "exportFailed": "Export failed",
       "audiolessEpub": "KOReader EPUB",
       "audiolessEpubHint": "Download EPUB for KOReader with audio files removed",
-      "noAudio": "no audio"
+      "noAudio": "no audio",
+      "textOnlyEpub": "Text-only EPUB",
+      "textOnlyEpubHint": "Download a narration-free EPUB while preserving reading anchors.",
+      "originalNarrated": "Original EPUB with narration",
+      "originalNarratedEpub": "Original EPUB with narration"
     },
     "sort": {
       "moveUp": "Move up",
@@ -12677,5 +12681,40 @@
     "errors": {
       "generic": "TTS error"
     }
+  },
+  "delivery": {
+    "readAloud": {
+      "label": "Read-aloud EPUB delivery",
+      "automatic": "Automatic: prefer text-only, allow original fallback.",
+      "textOnly": "Text-only EPUB",
+      "original": "Original EPUB with narration",
+      "hint": "Applies to future deliveries. Originals preserve existing narration and can be much larger. Text-only preparation fails if a safe copy cannot be made.",
+      "koboHint": "Original EPUBs bypass KEPUB conversion. Native Kobo firmware may not play narration, and precise position and highlight sync are unavailable for that copy.",
+      "profileHint": "Use separate OPDS profiles for readers that need different EPUB variants.",
+      "replacementTitle": "Replace a Kobo copy",
+      "bookId": "Book ID",
+      "device": "Device",
+      "prepare": "Prepare replacement",
+      "offer": "I removed only the device copy; offer the replacement",
+      "confirm": "I installed the replacement",
+      "cancel": "Cancel replacement",
+      "replacementHint": "Prepare and review first. Removing a device copy does not delete the library book. Back up device-local notes yourself. BookOrbit preserves canonical progress and server annotations. Delayed events can limit precise sync.",
+      "prepared": "Replacement prepared: {format}, {size}. Remove this book only from the selected device, then offer the prepared replacement and sync.",
+      "offered": "Replacement offered. Sync and download on the device, then confirm installation. A completed HTTP transfer does not prove installation.",
+      "cancelled": "Replacement cancelled. Cancellation does not restore a removed or partially replaced device copy. Select the same book to prepare a recovery download.",
+      "failed": "Could not prepare or update this replacement.",
+      "searchBook": "Search for a book",
+      "chooseBook": "Select a book",
+      "moreResults": "Show more books",
+      "noResults": "No matching books found.",
+      "refresh": "Refresh delivery status",
+      "confirmed": "You confirmed installation. This records your confirmation, not device verification.",
+      "transferred": "The transfer completed. Open the replacement on the device before confirming installation.",
+      "koreaderDefaultTitle": "KOReader EPUB delivery",
+      "koreaderDefaultHint": "The default applies to future downloads on devices using these credentials. Device settings can override it. Existing copies and interrupted downloads stay unchanged. Automatic preserves existing device choices.",
+      "koreaderUseDefault": "Use credential default",
+      "koreaderSaveFailed": "Could not save the KOReader EPUB delivery setting. Try again.",
+      "koreaderSaved": "KOReader EPUB delivery setting saved."
+    }
   }
 }