fix(import): restore favorite + pinned on import/backup restore

A pinned entry came back unpinned after export→import. Wider than pinned:
`favorite` was WRITTEN into the export/backup/sync containers but nothing
ever read it back — not parseEntriesFromJSON, not encryptImportEntry, not
the server INSERTs. So it was a write-only field, and a restore silently
dropped both flags. `pinned` wasn't in any container at all.

Wired the full round-trip:
- containers: export + auto-backup now carry `pinned` (favorite was there).
- parseEntriesFromJSON reads both back (absent → 0, e.g. foreign CSV).
- encryptImportEntry passes them through to the body.
- server create + bulk-import INSERTs write favorite/pinned
  (GetValue<Boolean>(..., False) → 0 default). PUT still ignores them, so a
  sync update can't clobber local flags.

Sync stays device-local as decided 2026-07-11: buildSyncSnapshot now OMITS
favorite explicitly (it was dead weight before; with the passthrough live,
leaving it in would have started propagating it). Commented so the intent
isn't re-broken.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

js/app.backup.js

@@ -207,7 +207,7 @@ async function runAutoBackupNow(silent) {
                 uuid: e.uuid || '',
                 site: e.site, title: e.title || '', username: e.username,
                 password: plain, folder: e.folder, tags: parseTags(e.tags),
-                favorite: !!e.favorite, totp_secret: plainTotp,
+                favorite: !!e.favorite, pinned: !!e.pinned, totp_secret: plainTotp,
                 kind: e.kind || 'login',
                 template: e.template || '',
                 custom_fields: plainCustom,