docs: add CLI reference and fix doc-code alignment gaps

[cursor]

Summary

Triggered by the push of commit 2ab49c5 (HTTP 409 docs for policy-blocked promote/rollback). This pass audits existing docs against source code and fills gaps.

Docs added

docs/cli.md (new)

Full CLI reference covering every command and subcommand:

• flightdeck init, doctor, serve
• release register/list/show/verify/diff/promote/rollback/history
• pricing import/show
• policy set/show
• runs ingest

Includes flag tables, exit codes, example output, and an end-to-end workflow walkthrough. Codepaths covered: src/flightdeck/cli/main.py (entire file).

Docs updated

docs/release-artifact.md

• Fixed schema filename: was release_artifact.schema.json, actual file is release.schema.json.

docs/http-api.md

• Fixed GET /v1/releases checksum example: was "sha256:..." but bundle_checksum() returns a raw hex digest with no sha256: prefix (verified in src/flightdeck/bundle.py).

docs/operations-and-policy.md

• Fixed table count: said "five tables" but listed six. Updated to "six domain tables" and added note about schema_migrations and pricing_import_audit.

RELEASE_NOTES.md

• Fixed trust boundary section: "there is no HTTP auth" was inaccurate — FLIGHTDECK_LOCAL_API_TOKEN gates POST /v1/promote and POST /v1/rollback. Replaced with an accurate two-tier access description (loopback default vs Bearer token when configured).

Key knowledge gaps addressed

• No in-repo CLI reference existed; developers had to read source or run --help for every flag.
• Four doc-code mismatches that could mislead integrators (wrong schema filename, wrong checksum format, inaccurate auth claim).