Auditor scaffold: types + Gitea client + policy stub + README

All-Bun sub-agent that watches open PRs on Gitea, reads ship-claims,
and hard-blocks merges when the code doesn't back the claim. First
commit of N; this is the skeleton. Dynamic/static/inference/kb checks
+ poller land in follow-up commits on this same branch.

- auditor/types.ts — Claim, Finding, Verdict, PrSnapshot shapes
- auditor/gitea.ts — minimal API client (listOpenPrs, getPrDiff,
  postCommitStatus, postReview). Live-proven: returned 0 open PRs
  against our repo (which IS the current state — every commit today
  went to main directly, which is the problem this auditor is meant
  to prevent)
- auditor/policy.ts — stub `assembleVerdict` + severity rules.
  Intentionally conservative defaults: strong claim + zero evidence
  = block, not warn.
- auditor/README.md — how to run + the hard-block mechanism

Workflow discipline change: starting with this branch, no more
direct pushes to main. Every change lands as a PR. When this
auditor is fully built and running, it'll review its own
completion PR — the recursive self-test.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

auditor/README.md

@@ -0,0 +1,53 @@
+# Lakehouse Claim Auditor
+
+A Bun sub-agent that watches open PRs on Gitea, reads the ship-claims
+in commit messages and PR bodies, and **hard-blocks** merges when the
+code doesn't back the claim.
+
+Rationale: when "compiles + one curl works" gets called "phase shipped,"
+placeholder code accumulates. This auditor runs every 90s, fetches
+each open PR, and subjects it to four checks:
+
+1. **Static diff** — grep/parse looking for placeholder patterns
+2. **Dynamic** — runs the never-before-executed hybrid test fixture
+3. **Cloud inference** — asks `gpt-oss:120b` via `/v1/chat` to
+   identify gaps in the diff
+4. **KB query** — looks up `data/_kb/` + observer for prior failure
+   patterns on similar claims
+
+Verdict is assembled, posted to Gitea as:
+- A **failing commit status** (hard block — branch protection
+  prevents merge)
+- A **review comment** explaining every finding
+
+## Run manually
+
+```bash
+cd /home/profit/lakehouse
+bun run auditor/index.ts
+```
+
+Defaults: polls every 90s, stops on `auditor.paused` file present.
+
+## State
+
+- `data/_auditor/state.json` — last-audited head SHA per PR
+- `data/_auditor/verdicts/{pr}-{sha}.json` — per-run verdict record
+
+## Where YOU edit
+
+`auditor/policy.ts` — the verdict assembler. Controls which findings
+block vs warn vs inform. All other code is mechanical: fetching,
+running checks, posting to Gitea.
+
+## Hard-block mechanism
+
+1. Commit status is posted as `failure` with context `lakehouse/auditor`
+2. If `main` branch protection requires `lakehouse/auditor` status
+   to pass, Gitea prevents merge
+3. When code is fixed and re-audit passes, status flips to `success`,
+   merge unblocks
+
+Enable branch protection (one-time, via Gitea UI or API):
+- `POST /repos/profit/lakehouse/branch_protections`
+- `{"branch_name": "main", "required_status_checks": {"contexts": ["lakehouse/auditor"]}}`