feat: claude-code reviewer engine (#2)

Phase 1: a second review engine alongside the majordomo agent loop. For
each lens, shell out to the Claude Code CLI (`claude -p --output-format
json`) inside the checked-out repo so it verifies findings with its own
read tools, then reuse gadfly's verdict-parse + recheck + consolidate +
emit pipeline. Select via GADFLY_MODELS `claude-code`/`claude-code/<model>`;
auth via CLAUDE_CODE_OAUTH_TOKEN (no --bare) else ANTHROPIC_API_KEY;
read-only by default; GADFLY_CLAUDE_* knobs. Dockerfile bundles Node +
@anthropic-ai/claude-code. Also bumped the dogfood pin to the status-board
image (PR #2 was the first dogfood with the live board + full fleet).

Folded in the swarm's own review findings: minimal subprocess env (no
GITEA_TOKEN leak to the CLI), runPass robustness (ctx/empty-result/runErr),
process-group cleanup on timeout, rune-safe error truncation, and
engine-neutral prompts (also de-mort-ified the recheck prompt). 66 findings
graded via the gadfly MCP.

gofmt clean, go vet quiet, go build + go test -race green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Steve Dudenhoeffer <steve@stevedudenhoeffer.com>
Co-committed-by: Steve Dudenhoeffer <steve@stevedudenhoeffer.com>

examples/README.md

@@ -10,6 +10,7 @@ set the secrets/vars it references. Gadfly is advisory only — it never blocks
 | [`local-ollama.yml`](local-ollama.yml) | a **local/LAN Ollama** daemon | nothing (or `GADFLY_BASE_URL` for a remote host) |
 | [`openai-compatible.yml`](openai-compatible.yml) | any **OpenAI-compatible** endpoint (local Ollama `/v1`, gateway, vLLM, OpenRouter…) | `GADFLY_BASE_URL` (+ a key for most gateways) |
 | [`endpoint-aliases.yml`](endpoint-aliases.yml) | **several named backends** at once (one comment each) | repo vars `GADFLY_ENDPOINT_<NAME>` |
+| [`claude-code.yml`](claude-code.yml) | the bundled **Claude Code CLI** engine (`claude-code/<model>`) | secret `CLAUDE_CODE_OAUTH_TOKEN` (or `ANTHROPIC_API_KEY`) |
 | [`.gadfly.yml`](.gadfly.yml) | **per-repo specialist config** (not a workflow — goes at your repo root) | — |
 
 Common to all:

examples/claude-code.yml

@@ -0,0 +1,71 @@
+# Gadfly reviewing via the Claude Code CLI engine.
+# Copy to .gitea/workflows/adversarial-review.yml in your repo.
+#
+# Instead of a majordomo model, each lens shells out to the bundled `claude` CLI
+# inside the checked-out repo (it uses its own Read/Grep/Glob tools to verify
+# findings), then Gadfly runs its usual verdict + recheck + consolidate pipeline.
+#
+# Auth: a Pro/Max subscription token from `claude setup-token` (no --bare),
+# stored as the CLAUDE_CODE_OAUTH_TOKEN secret. Falls back to ANTHROPIC_API_KEY
+# if you'd rather pay per-token — set only ONE.
+#
+# Heads-up: this engine is wired but not yet validated end-to-end here, and using
+# subscription auth in automated CI is a gray area in Anthropic's terms — read
+# the README's "Claude Code engine" note before relying on it.
+
+name: Adversarial Review (Gadfly)
+
+on:
+  pull_request:
+    types: [opened, reopened, ready_for_review]
+  issue_comment:
+    types: [created]
+  workflow_dispatch:
+    inputs:
+      pr_number: { description: "PR number to review", required: true }
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+concurrency:
+  group: gadfly-${{ github.event.issue.number || github.event.pull_request.number || github.event.inputs.pr_number }}
+  cancel-in-progress: true
+
+jobs:
+  review:
+    # Security: only trusted users may trigger a secret-bearing run via a PR
+    # comment. Replace the username(s) below with your maintainers — keep them in
+    # sync with GADFLY_ALLOWED_USERS (the in-container belt-and-suspenders check).
+    if: >-
+      github.event_name != 'issue_comment'
+      || github.actor == 'your-username'
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: docker://gitea.stevedudenhoeffer.com/steve/gadfly:latest
+        env:
+          GITEA_API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          # --- Claude Code engine ---
+          # Pro/Max subscription token (preferred). Or set ANTHROPIC_API_KEY
+          # instead for per-token billing — but never both.
+          CLAUDE_CODE_OAUTH_TOKEN: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          # ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
+          # bare "claude-code" uses the CLI default model; "claude-code/<model>"
+          # sets --model (sonnet/opus/haiku, or a full id). One comment per entry.
+          GADFLY_MODELS: "claude-code/sonnet"
+          # Optional CLI tuning (defaults are read-only-safe):
+          # GADFLY_CLAUDE_PERMISSION_MODE: plan          # read-only; never edits
+          # GADFLY_CLAUDE_ALLOWED_TOOLS: "Read,Grep,Glob"
+          # GADFLY_CLAUDE_EXTRA_ARGS: "--max-turns 30"
+          GADFLY_ALLOWED_USERS: "your-username"
+          # --- event context (leave as-is) ---
+          EVENT_NAME: ${{ github.event_name }}
+          PR: ${{ github.event.pull_request.number || github.event.issue.number || github.event.inputs.pr_number }}
+          PR_BRANCH: ${{ github.head_ref }}
+          IS_DRAFT: ${{ github.event.pull_request.draft }}
+          COMMENT_BODY: ${{ github.event.comment.body }}
+          COMMENT_ID: ${{ github.event.comment.id }}
+          ACTOR: ${{ github.actor }}