meta-improve

# Constrained self-improvement The public verb is `/meta-improve-vault`. ## Input and gate Select only from canonical `vault/memory/DREAM_LOG.md`: an exact candidate whose `status` is `approved` and whose approval was written by `/dream --set-status` from a direct operator decision. `proposed` is not approval. Read only the exact evidence references named by that approved candidate from `vault/memory/runtime/LESSONS.jsonl` and `vault/memory/runtime/NIGHTLY_CAPTURE_CANDIDATES.jsonl`. Those products provide traceability; they never provide approval by themselves. Before Build: ```text node daemons/nightly-contracts.mjs meta --root <aigent-root> \ --candidate <candidate-id> ``` Require `META_GATE PASS`. It checks the canonical block for exact approved status and non-placeholder operator evidence. This is the executable `nightly-contracts.mjs meta` gate. ## Build For one approved candidate: 1. Re-read its evidence, proposed change, mutation proof, and scope. 2. Use repository isolation where normal policy requires it. 3. Apply the smallest change satisfying the proposal. 4. Run the real red-before and green-after proof plus relevant system checks. 5. Produce a review artifact with exact diff, commands, exits, residual risks, and rollback. 6. Surface `accept / reject / revise` to the operator. Never merge, push, deploy, broaden scope, modify an operator gate, approve another candidate, or infer approval. A failed proof asks the Dream writer to set the candidate `bl...