[kvlonge]

Why

Fensu v0.16.0 made typed file/project subjects, deterministic project-tree queries, subject-aware project caching, and the resolved Python architecture graph public. The custom-rule documentation still described only legacy module callbacks.

Changes

• document typed File and Project callback shapes
• describe exactly-once, source-independent project rules
• add ctx.project.tree and ctx.graph references
• document project cache subjects and query-specific invalidation
• retain the legacy Python AST callback as an explicit escape hatch

Verification

• git diff --check
• current-tree public repository hygiene scan
• independent contract review against the v0.16.0 source: no findings