Improve query and path result fidelity

[forhappy]

Summary

• require exact endpoint resolution for compass path, report resolved identities, and return bounded unreachable diagnostics
• rank paths by relationship strength while disclosing a shorter weaker alternative when relevant
• make natural-query fallback confidence explicit and prevent generic relational vocabulary from becoming discovery seeds
• provide concise default query output, add --evidence, and increase the default text budget
• recover exact Rust calls through source-proven Arc, Rc, and Box receiver chains, typed chained-call results, and bounded evaluating local macros
• update compatibility, migration, command, configuration, implementation, and user documentation

Compatibility

• JSON response schemas remain unchanged
• human-readable query output changes intentionally
• discovery text cursors advance to version 2; callers should restart pagination from the first page
• Rust universal evidence advances to producer version 2; cached Rust evidence rebuilds automatically, with no graph schema migration

Verification

• cargo fmt --all -- --check
• cargo clippy --workspace --lib --bins --locked -- -D warnings
• cargo test --workspace --lib --bins --locked
• targeted Rust evidence and query/CLI regression suites
• five pinned real-repository release graph rebuilds and ten source-grounded CLI tasks
• 500-query relevance qualification
• cargo test -p compass-cli --test compass_product --locked
• sh scripts/check_product_boundary.sh
• ./scripts/qualify_code_graph_v1.sh --fixtures-only
• universal evidence promotion validator and tests
• git diff --check