improved tools for ai

docs/runbooks/error-codes.md

@@ -0,0 +1,113 @@
+# Error Codes Runbook
+
+Purpose: provide consistent, AI-readable error categories for faster autonomous debugging.
+
+## Format
+
+Use codes in this format: `<SUBSYSTEM>-<CATEGORY>-<ID>`
+
+Examples:
+
+- `BE-EXPORT-001`
+- `FE-WAVEFORM-002`
+- `HOST-BRIDGE-003`
+
+## Backend (FastAPI / Services)
+
+### Export
+
+- `BE-EXPORT-001`: Export request validation failed.
+  - Symptoms: HTTP 400, missing/invalid ranges.
+  - Likely causes: malformed payload, empty segments.
+  - First checks: request body shape, keep/mute/gain ranges.
+
+- `BE-EXPORT-002`: FFmpeg command failed.
+  - Symptoms: HTTP 500, stderr contains filter/codec error.
+  - Likely causes: invalid filter chain, unsupported codec/container.
+  - First checks: generated FFmpeg args, source media codec, target format.
+
+- `BE-EXPORT-003`: Caption burn-in/subtitle generation failed.
+  - Symptoms: burn-in export fails while plain export works.
+  - Likely causes: ASS generation issue, subtitle path/temp file cleanup race.
+  - First checks: ASS file generation, temp file lifecycle.
+
+### Transcription
+
+- `BE-TRANSCRIBE-001`: Model unavailable or download failure.
+  - Symptoms: transcription never starts or exits early.
+  - Likely causes: missing model, network/cache issue.
+  - First checks: model cache path, ensure-model logs.
+
+- `BE-TRANSCRIBE-002`: Inference pipeline runtime failure.
+  - Symptoms: mid-run crash, partial output.
+  - Likely causes: CUDA/CPU mismatch, unsupported media, resource exhaustion.
+  - First checks: environment, GPU availability, media decoding logs.
+
+### Audio / Waveform
+
+- `BE-AUDIO-001`: Waveform endpoint failed.
+  - Symptoms: waveform panel shows unavailable/error.
+  - Likely causes: decode error, invalid file path, unsupported media input.
+  - First checks: `audio/waveform` response body, file existence, FFmpeg decode path.
+
+## Frontend (React)
+
+### Timeline / Zones
+
+- `FE-TIMELINE-001`: Zone interaction state inconsistency.
+  - Symptoms: cannot drag/select/delete zones predictably.
+  - Likely causes: stale selection/editing state, hidden/selected mismatch.
+  - First checks: zone mode flags, selectedZone state transitions.
+
+- `FE-TIMELINE-002`: Visibility filter mismatch.
+  - Symptoms: hidden zones still interactive or selected.
+  - Likely causes: hit-testing ignores visibility flags.
+  - First checks: hit-test filters and selected-zone reset logic.
+
+### Media UI
+
+- `FE-WAVEFORM-001`: Waveform fetch failed.
+  - Symptoms: warning banner with URL/error.
+  - Likely causes: backend unavailable, bad path encoding, CORS/proxy issue.
+  - First checks: backend health endpoint, waveform URL, network tab logs.
+
+- `FE-PROJECT-001`: Project load mismatch.
+  - Symptoms: loaded media/transcript differs from saved data.
+  - Likely causes: schema drift, fallback URL mismatch.
+  - First checks: project schema fields, loadVideo/loadProject URL parity.
+
+## Host / Bridge (Tauri)
+
+- `HOST-BRIDGE-001`: Desktop API bridge unavailable.
+  - Symptoms: open/save/transcribe actions no-op or throw.
+  - Likely causes: bridge init error, host command mismatch.
+  - First checks: bridge initialization, command names, runtime environment.
+
+- `HOST-WEBKIT-001`: Linux WebKit startup/render regression.
+  - Symptoms: noisy startup errors, UI load issues.
+  - Likely causes: CSP/font regressions, unsupported protocol calls.
+  - First checks: CSP config, remote font usage, bridge fallback behavior.
+
+## Logging Guidance
+
+When raising errors, include:
+
+1. Error code.
+2. Human message.
+3. Correlation/request id.
+4. Relevant paths/ids (sanitized).
+5. Suggested first-check hints.
+
+Example structured payload:
+
+```json
+{
+  "code": "BE-EXPORT-002",
+  "message": "FFmpeg export failed",
+  "requestId": "exp_20260415_001",
+  "context": {
+    "format": "mp4",
+    "mode": "reencode"
+  }
+}
+```