Sync beta with 0.9.126 integrations and local follow-up fixes

[Talal1011]

Purpose

Bring upstream beta-branch up to date with the reconciled local Beta 0.9.126 release work and subsequent local tracker fixes. This is a source-integration PR, not a new release or a claim that the published 0.9.126 binaries contain every follow-up here.

• Based on upstream f6ce611e (Kawaii theme fixes), including 96f52ac7 (subtitle adjustment).
• Local integration source: 5d53240f106742861d7a00387d832d898d06001c.
• Published 0.9.126 baseline: e758926e07b34ee260284f0d4428eeee0e3b1eeb.
• Latest PR fix(cw): dismissed cards resurface on further progress from any source #1411 follow-ups are included: remote-progress refresh/retry, immediate source-toggle removal and pause-vs-stop handling below 90%.

Reviewable commit groups

1. HTTP redirect/provider credential boundaries.
2. Account session renewal and ordered display-name persistence.
3. Subtitle language identity, manual timing and selection ownership.
4. Continue Watching, anime identity, tracker queues and updated fix(cw): dismissed cards resurface on further progress from any source #1411.
5. Manga downloads, source browsing and progress tracking.
6. List ordering and descriptions.
7. Discover catalog caching and scrolling performance.
8. Native playback/window recovery, ebook voices and X-Ray navigation.
9. Current plugin runtime and manifest handling.
10. Native desktop notifications.
11. Managed updater recovery and persistent release notes.
12. Locale reconciliation and fallback coverage.
13. Dependencies, version metadata and packaging workflow.
14. Approved navigation, profile and settings integration.
15. Cross-feature regression coverage.

These are topic groups, not independently deployable releases. Validate the final tree together. Commit messages record the source snapshots and credit original contributors to the affected paths.

PR provenance

Carries the retained integrations from #1306, #1334, #1359, #1361, #1362, #1371, #1372, #1374, #1376, #1382, #1385, #1392, #1394, #1398, #1399, #1400, #1401, #1406, #1407, #1408, #1409, #1411, #1416, #1421 and #1422. Existing updater work from #1381, #1383 and #1389 is not replayed as duplicate PR merges.

• Discord OAuth2 #1396 Discord account OAuth is not restored. Discord Rich Presence is separate.
• fix: improve RTL support, multiview interactions, and keyboard navigation #1379 is not imported wholesale: retain the reconciled navigation work and the standard row-arrow restoration, with the split fix(rtl): improve Big Picture navigation, poster dock, and live-tv multiview #1406/fix(navigation): extend TV navigation to all categories, fix settings focus, and improve home search #1408 integrations.

🛑🛑 UI changes 🛑🛑

This PR carries previously approved local UI changes: TV/controller and RTL navigation, standard row arrows, ElegantFin alignment, profile-picker background controls, list descriptions/reordering, Continue Watching artwork, X-Ray actor browsing, persistent changelogs and the newer plugin settings presentation. Review these against Harbor's design system. No additional redesign is intended by this sync.

Reconciliation and exclusions

The release branch contains cherry-picked upstream work under different commit IDs. The last imported upstream snapshot (2518bf96) was used to reconcile the net local changes without undoing newer upstream work. Three textual locale conflicts were resolved by comparing string keys and values; there were no conflicting value edits. New upstream wording was preserved alongside the local feature entries.

Excluded internal QA notes, announcement drafts, local benchmark output, backups, untracked diagnostics and the removed uncommitted motion experiment. No secrets or signing material are included. An added-line credential/path pattern scan found no matches; this is not a substitute for security review.

Verification

• pnpm run typecheck.
• pnpm test: 1,292 passed, 22 skipped, 0 failed (1,314 total).
• pnpm run check on changed frontend/script files in Windows-safe batches; configuration formatting checked separately.
• cargo check --manifest-path src-tauri/Cargo.toml --locked on Windows.
• cargo test --manifest-path scripts/http-redirect-tests/Cargo.toml --locked --lib: 7 passed.
• git diff --check; clean integration worktree.
• Fresh Linux full binary using pnpm tauri:build:linux-system (not available locally; Windows host has no WSL).
• Fresh macOS/Linux runtime smoke tests and post-integration manual UI/playback checks.
• Upstream PR CI.

Whole-repository formatting initially reported 4,132 files; unrelated files were not reformatted. The Windows Rust check retains two existing unused VapourSynth helper warnings. Vite+ also reports existing configuration deprecation notices.

Integration-specific test repairs: normalize Cargo.lock CRLF when testing versions, keep bundled-note tests independent of an excluded announcement draft, update a stale fullscreen source assertion, and register eight existing UI strings in the English fallback catalog (not claimed as translations). The missing Arabic skip-reason label is translated.

Release safety

No tags, updater feeds, release records or published binaries are changed by this PR. Do not merge automatically. Native packaging changes remain manual/tag-triggered. Keep this PR in draft until the remaining validation and review are complete.