[kvlonge]

Why

Fensu 0.19.0 adds aggregate custom rules that compare explicit named analyzer targets. The public docs need to explain their top-level policy ownership, typed target handles, diagnostics, and cache behavior.

Changes

• add a repository-rules concept guide with configuration and a complete Python example
• document aggregate-only execution and target-scoped skipping
• describe target-local Python, Rust, web, tree, and graph facts plus repository path translation
• document target-registry and runtime-observed cache invalidation
• link repository rules from configuration, custom rules, RuleContext, and fensu check

Verification

• validated docs.json as JSON
• checked the complete diff for whitespace errors and internal navigation targets
• public-repository hygiene scan passed
• independent docs review completed; its minimum-target finding was fixed and confirmed