feat(federation): certify graph profile and evaluation

[tcballard]

Stack

1. docs(federation): ratify graph-complete v0.29 scope #462 — ratify graph decisions
2. feat(federation): establish graph engine foundation #463 — graph foundation
3. feat(federation): activate verified corpus graphs #464 — activate the verified graph engine
4. This PR — certify profile guidance and evaluation

What this adds

• v2-first decided init --parent-corpus guidance while retaining the v1 command and byte-identical output when guidance is not requested
• an extension of the existing DecisionGrounding evaluator, not a separate benchmark
• a graph fixture with three direct parents, nested v1 and v2 ancestry, 45 visible Decisions, and a 32-inbound hard negative
• committed graph baseline and floors:
  • overall/category P@1 >= 0.90
  • R@5 >= 0.95
  • zero negative violations
  • tolerance 0.02
• CLI documentation and roadmap evidence

Validation

The complete tree is byte-identical to the fully validated integration tip.

• full workspace tests — passed
• full workspace all-target clippy with warnings denied — passed
• graph evaluation — 2/2
• CLI suite — 17/17
• graph CLI contract — 9/9
• graph MCP contract — 5/5
• corpus validation — 468 valid, 0 invalid, 12 skipped
• relationships — 3,055 checked, 0 issues
• gate — 0 blocking, 134 existing advisories
• review — 508 non-blocking issues, health 96
• agent-rules drift check — in sync
• Linux, Windows, and macOS cross-platform certification — passed

The federation requirements intentionally remain Proposed and the roadmap remains Planned until the implementation stack is reviewed and merged.

Closes #271
Closes #267

[tcballard]

Cross-platform certification — passed

The complete native matrix passed for this PR head.

• Linux: native release build; export-schema contracts; inotify/stat freshness; workspace unit and bounded regression suites; strict all-target Clippy; authoritative spec registry and byte-vector guards; MCP compatibility vectors; live-corpus invariants
• Windows: native release build; CLI and cache/store runtime smoke; MCP contract smoke
• macOS: native release build; CLI and cache/store runtime smoke; MCP contract smoke
• Dependency policy: cargo-deny passed
• PR checks: passed

Workflow evidence: rust-spike run #208 (run ID 31387291629); PR Checks run #531.