[F2.2] Validate all documented API behaviors

[metaphorics]

Question

Implement sync, async, filesystem, protocol, project, checker, snapshot, completion, and reference API behavior without exclusions, compatibility shims, or copied reference code.

Blocked by

• Close performance and formal correspondence

Spine anchor

Ive — this leaf serves one bounded product obligation and one evidence ledger.

Acceptance

.outline/gates/F2.2.md reports every gate checked with current, non-pending evidence.