[SizzleUnrlsd]

Summary

Third and last deliverable of the product track: the usage documentation.

• Acceptance tests first (test: define what the usage documentation covers): the guides must name every command-line option, every rule the shipped plugins can report, the three report formats and the exit codes, every plugin base class and model kind of the plugin API, every bundled plugin, and every command they show must use options that exist.
• docs/usage.md: install, quick start, the option table, what is analysed and how taint travels, the rules grouped by family with their triggers and how flows are judged, the text, JSON and SARIF reports, advisories (OSV import, local file format), policy and SBOM, cache and jobs, the bundled plugins, a GitHub Actions example uploading SARIF, use from Python, the supported syntax and the intermediate representation.
• docs/plugins.md: plugin layout and loading, the manifest fields, canonical symbols, one example per kind of plugin (SymbolCallDetector, TaintDetector, ModelPlugin with the table of the ten model kinds and advisories, SecretDetector, ProjectPlugin, raw Plugin with the analyses it can read), findings, and how to test a plugin with the engine.
• README trimmed to an overview with the install command and links to the three documents; its stale description of the pipeline as "deferred" is gone, and the long option-by-option prose moved into the usage guide.