feat(calibre): add Readest calibre plugin to push books and metadata (#4918)

* feat(calibre): add Readest calibre plugin to push books and metadata (#4863)

Add apps/readest-calibre-plugin, a calibre GUI plugin that uploads
selected books with their metadata into the user's Readest cloud
library, modeled on BookFusion's open-source plugin.

- Selective manual push from the calibre toolbar with per-book status
  (uploaded / updated / up to date / failed) and quota handling
- Books are content-addressed with the same partial MD5 as the apps,
  so re-pushing updates the existing entry instead of duplicating;
  metadata edits re-push without re-uploading the file
- Metadata mapping includes series, tags, identifiers and optional
  calibre custom columns; carries over server-side fields (progress,
  reading status, grouping, cover) that POST /sync would null out
- Auth mirrors readest.koplugin and the desktop app: email/password
  plus browser OAuth (Google/Apple/GitHub/Discord) through a localhost
  callback server with the fragment-to-query relay
- Pure-logic modules (api.py, wire.py, oauth.py) are calibre-free and
  covered by 56 unit tests (make test); make zip builds the plugin

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

* ci(release): package readest-calibre-plugin in releases

Mirror the KOReader plugin packaging: a build-calibre-plugin job stamps
PLUGIN_VERSION in __init__.py with the release version from
apps/readest-app/package.json, builds the zip via make, and uploads
Readest-<version>.calibre-plugin.zip to the GitHub release. The version
committed in git stays a development placeholder.

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

* chore(agent): add calibre plugin project memory

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

* feat(calibre): embed metadata in OPF and dedupe by calibre uuid

Rework book identity so metadata can be embedded into the uploaded file
without creating duplicates, as requested in review:

- Embed calibre metadata (including custom columns) into a temporary
  copy of the book file at upload time via calibre's set_metadata; the
  library file is never modified
- Dedupe by the calibre book uuid carried in the entry's metadata
  identifier, which survives file-byte changes, with a live-row
  preference when both hash and uuid match rows
- Detect file content changes via calibreSourceHash, the raw library
  file fingerprint stored in the pushed metadata, so detection works
  from any machine; v1 rows fall back to book_hash which equals the
  raw hash for them
- A changed file now replaces the old entry in one sync push (new row
  with carried-over reading status, grouping, progress and created
  date, plus a tombstone for the old row) and deletes the old cloud
  files to reclaim quota
- Metadata-only edits still update the library entry without
  re-uploading the file

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

* chore(calibre): set copyright holder to Bilingify LLC

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

.github/workflows/release.yml

@@ -118,6 +118,33 @@ jobs:
           echo "Uploading ${plugin_zip} to GitHub release"
           gh release upload ${{ needs.get-release.outputs.release_tag }} ${plugin_zip} --clobber
 
+  build-calibre-plugin:
+    needs: get-release
+    permissions:
+      contents: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: create calibre plugin zip
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          version=${{ needs.get-release.outputs.release_version }}
+
+          # Stamp PLUGIN_VERSION in __init__.py with the release version
+          # (from apps/readest-app/package.json, mirroring the koplugin's
+          # _meta.lua stamp above); the committed value is a dev placeholder.
+          version_tuple=$(echo "${version}" | awk -F. '{printf "(%d, %d, %d)", $1, $2, $3}')
+          perl -i -pe "s/^PLUGIN_VERSION = \(\d+, \d+, \d+\)/PLUGIN_VERSION = ${version_tuple}/" \
+            apps/readest-calibre-plugin/__init__.py
+
+          make -C apps/readest-calibre-plugin zip
+          plugin_zip="apps/readest-calibre-plugin/dist/Readest-${version}.calibre-plugin.zip"
+
+          echo "Uploading ${plugin_zip} to GitHub release"
+          gh release upload ${{ needs.get-release.outputs.release_tag }} ${plugin_zip} --clobber
+
   build-tauri:
     needs: get-release
     permissions: