docs: document the Gadfly adversarial review loop in CLAUDE.md

Records the PR workflow: push work to a PR (never straight to main), wait for
Gadfly to finish and weigh its findings, then grade each finding back to the
gadfly-reports MCP (record_finding_grade / list_findings / scoreboard) so the
telemetry can measure whether each model earns its keep.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -129,6 +129,27 @@ CI: `.gitea/workflows/ci.yaml` (Gitea Actions, mirrors foreman). README.md
 must match reality in the same commit that changes behavior — no
 aspirational docs; unbuilt features are marked pending in the matrix.
 
+## Adversarial review loop (Gadfly)
+
+Ship work through PRs and let Gadfly review it before merge:
+
+- **Push to a PR, never straight to `main`.** Branch, push, open a PR.
+  `.gitea/workflows/adversarial-review.yml` runs Gadfly (the standalone
+  agentic adversarial reviewer) — a full fleet of 9 ollama-cloud models +
+  the M1/M5 Macs via foreman, each running the 3-lens suite (security,
+  correctness, error-handling). Advisory only; it never blocks the merge.
+- **Wait for Gadfly to finish, then read its output.** Don't merge while the
+  review is still running. Each model posts one consolidated comment; weigh
+  every finding on its merits and fix the real ones (Gadfly is a simple
+  system — findings are advisory, so confirm before acting).
+- **Grade the findings back to the Gadfly MCP.** For each finding, call
+  `mcp__gadfly__record_finding_grade`: `is_real=true` + a `severity`
+  (trivial|small|medium|high|critical) for a genuine problem, or
+  `is_real=false` for a false positive; add `notes`/`usefulness` when
+  useful. Use `mcp__gadfly__list_findings` (`only_ungraded=true`) to find
+  what still needs grading and `mcp__gadfly__scoreboard` for the per-model
+  rollup. This telemetry is how we measure whether each model earns its keep.
+
 ## Out of scope (anti-creep)
 
 No persistent store (health is in-memory behind the registry), no