Castwright 1.6.0

Castwright 1.6.0

Seed release for in-app self-upgrade. From here, future versions install
themselves from a hand-delivered bundle (Account → Application updates), on top
of a round of reliability, observability and listening polish.

⚠️ Upgrade note: the jump into 1.6.0 is manual; 1.6.0 → 1.7.0 is the
first self-upgrade.

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✨ Headline features

🚀 Update from inside the app (new)

One-click cross-version upgrades for hand-delivered alpha bundles (fs-1).

• Versioned-directory install layout — releases/vX.Y.Z/ + a stable
  launch.mjs + shared workspace/ / venv/ / models/ siblings, so the
  running release is never touched and rollback is just not flipping the pointer.
• Safe migrations — a boot coordinator backs up every workspace JSON before
  migrating; a top-bar version pill + what's-new banner surface the running version.

🌍 Multi-language — Russian (new)

A book-level BCP-47 language field, end to end (fs-2, language half).

• Cyrillic auto-detection + a confirm-step selector; designed Qwen voices
  speak the book's language; Cyrillic-aware analyzer token estimates and
  per-language attribution; a Listen language badge.
• Never-cross-language invariant force-routes non-English books to Qwen
  (Kokoro is English-only) and blocks any silent cross-language fallback. English
  books are byte-identical to before.

🩺 Admin watch console (new)

The former dev-only Worktrees view is now an all-users Admin console at
#/admin (fs-18).

• Health board — green / amber / red on GPU / VRAM, TTS sidecar + resident
  models, analyzer connectivity, ffmpeg, free disk, from a new GET /api/diagnostics,
  plus generation throughput. The top-bar pill carries a health status dot.

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🎧 Listening experience

• Auto-advance / continuous playback — the mini-player advances to the next
  chapter and keeps playing, behind a default-on toggle (Account → Advanced), so
  a book plays hands-free end to end (fe-23).
• Skip forward / back — intra-chapter ±15s / ±30s seek in the mini-player
  with rebindable shortcuts (defaults J / L) and configurable deltas (fe-24).

🔊 Generation quality & reliability

• Post-synthesis audio QA — each finished chapter gets a cheap automated
  check (near-silent / clipped / truncated / runaway duration) and an advisory
  "Suspect" badge with the reason in Generate + Listen, so garbled or empty
  renders are flagged before the listener hits them (srv-27).
• Pre-flight disk-space guard — free space is checked against an estimate
  before a run or export and a warning is surfaced when it's tight (configurable
  to block) — no more failing 40 chapters into a run (srv-28).
• Silent generation stalls could leave a chapter showing a misleading
  "Queued" forever. Now a per-chapter no-progress watchdog records a real
  failure, leak-saturated orphan sidecars are no longer adopted, and the
  supervisor health-polls adopted sidecars.
• A Qwen reload doubled VRAM into the Windows sysmem-spill stall. Now the
  reload no longer doubles VRAM and the recycle watchdog also keys on reserved VRAM.
• "Design & compare" broke on a missing voice or a design-model race. Now it
  no longer breaks, and the persona prompt aligns with the official VoiceDesign format.
• Ungenerated chapters masqueraded as playable in the Listen view. Now Play /
  Share are gated on generated audio.

⚙️ Settings, observability & models

• Plain-language failure messages — recurring failures (sidecar down, VRAM
  spill, rate-limit, OOM, disk-full, model-not-loaded, timeouts) now show a
  human-readable message plus a "what to do next" line instead of a raw error
  string (fs-19).
• Per-run resource telemetry — per-chapter RTF, VRAM, host RAM and wall-time
  are logged and charted in a new Admin "Resource trends" panel for
  perf-regression visibility (fs-20).
• Auto-backup of state.json — scheduled per-book snapshots on a
  configurable cadence with retention + one-click restore from Account (srv-2).
• Power-user tuning — rebindable shortcuts, accessibility toggles
  (high-contrast + larger text) and an autosave-debounce knob, device-local (fe-2).
• In-app Coqui XTTS v2 installer, plus an A/B current-vs-proposed voice
  audition in the Qwen voice-design flow.

🏗️ Under the hood

• Dependency major upgrades — React 18→19, Vite 5→8 (Rolldown), Vitest 2→4,
  react-router 6→7, TypeScript 5→6 (plan 167); Zod 3→4, Express 4→5, pdfjs-dist
  4→5, Tailwind 3→4 (plan 170); GitHub Actions runners off the deprecated Node-20 majors.
• CI cost — path-filtered per-PR verify, draft-by-default + integration
  batching, a doc-only CI fast-path, and a local pre-push guard that refuses
  force-push / deletion of main.
• Release pipeline — three-way version lockstep (root + server + sidecar
  version.py), a cross-OS gate fired before tagging, and RELEASE_NOTES.md
  baked into the zip.

Full changelog: v1.5.1...v1.6.0