Targeted documentation fixes and additions covering knowledge gaps found by auditing the source code against the existing docs. All changes are verified against the implementation — no fabricated behavior.

Docs updated

docs/http-api.md

• New Web UI section — documents GET / serving the React UI from static/index.html and /assets/* static files; this route was missing entirely.
• run_id uniqueness scope — clarifies uniqueness is per-database (not "per workspace" as previously stated, which incorrectly implied workspace_id partitions the key).
• Empty events array — documents HTTP 422 response when "events": [] is sent (Pydantic min_length=1 constraint, previously undocumented).
• window format constraints — adds that N must be a positive integer; zero/negative/unsupported units return HTTP 400.

docs/cli.md

• Actor resolution — documents how the actor field written to the audit ledger is resolved: $USER (Unix) → $USERNAME (Windows) → "unknown". Clarifies that --actor is HTTP/SDK-only; the CLI resolves it automatically.

docs/operations-and-policy.md

• window format constraints — expands the compute_diff steps to enumerate valid units and note OperationError on bad input.
• New error row — Promoted baseline release is missing: rel_... in the Common errors table, covering the case where a promoted_releases pointer references a release row that no longer exists (manual DB edit or truncation). Includes cause and fix guidance.

Codepaths covered

• src/flightdeck/server/app.py (GET /, /assets/*, GET /health)
• src/flightdeck/server/routes/ingest.py (POST /v1/events, min_length=1 on request body)
• src/flightdeck/storage.py (run_id PRIMARY KEY, insert_run_events dedup)
• src/flightdeck/ledger.py (parse_window — positive int constraint, d/h/m units)
• src/flightdeck/operations.py (_evaluate_promotion_or_rollback — promoted baseline missing error)
• src/flightdeck/cli/main.py (actor_name() resolution logic)

Verification

• uv run python -m ruff check src tests — all checks passed
• uv run python -m pytest — 75 passed
• uv run flightdeck-quickstart-verify — OK