chore(ci): add Warden review setup and skill catalog

Wire Warden into PR review using the getsentry/warden GitHub Action.

- warden.toml: 13 skills total
  - 8 project-specific review skills scoped to the file lists in each
    SKILL.md (docs-release, packaging-resource, rendering-streaming,
    runtime-boundary, snapshot-fixture, structured-output, test-boundary,
    tool-contract)
  - 5 remote skills from getsentry/skills (find-bugs, security-review,
    gha-security-review, code-review, code-simplifier) scoped to the
    surfaces they apply to
- warden-sweep is intentionally not registered: invoke manually via
  warden --skill warden-sweep
- .github/workflows/warden.yml runs on opened/synchronize/reopened
- .agents/skills/ holds local skill sources (also exposed via
  .claude/skills symlink)

Author: cameroncooke

.agents/skills/warden-sweep/SKILL.md

@@ -0,0 +1,72 @@
+Fix a verified code issue. You are working in a git worktree at: ${WORKTREE}
+
+## Finding
+- Title: ${TITLE}
+- File: ${FILE_PATH}:${START_LINE}
+- Description: ${DESCRIPTION}
+- Verification: ${REASONING}
+- Suggested Fix: ${FIX_DESCRIPTION}
+```diff
+${FIX_DIFF}
+```
+
+## Instructions
+
+### Step 1: Understand the code
+Read the file at ${WORKTREE}/${FILE_PATH}. Read at least 50 lines above and below the reported location. Trace callers and callees of the affected code using Grep/Glob to understand how it is used. Do NOT skip this step.
+
+### Step 2: Apply a minimal fix
+Apply the smallest change that addresses the finding. If the suggested diff doesn't apply cleanly, adapt it while preserving intent. Do NOT refactor surrounding code, rename variables, add comments, or make any change beyond what the finding requires.
+
+### Step 3: Write tests
+Write or update tests that verify the fix:
+- Follow existing test patterns (co-located files, same framework)
+- At minimum, write a test that would have caught the original bug
+- Test the specific edge case, not just the happy path
+
+Only modify the fix target and its test file.
+
+### Step 4: Self-review
+Before staging, run `git diff` in the worktree and review every changed line. Verify:
+1. The change addresses the specific finding described, not something else
+2. No unrelated code was modified (no drive-by cleanups, no formatting changes)
+3. Trace through changed code paths: does the fix introduce any new bug, null reference, type error, or broken import?
+4. Tests exercise the fix (the failure case), not just that the code runs
+
+If ANY check fails, fix the problem before proceeding. If the suggested fix is wrong or would introduce a regression you cannot resolve, do NOT commit. Instead, skip to the output step and report why.
+
+### Step 5: Commit
+Do NOT run tests locally. CI will validate the changes.
+
+Stage and commit with this exact message:
+
+fix: ${TITLE}
+
+Warden finding ${FINDING_ID}
+Severity: ${SEVERITY}
+
+Co-Authored-By: Warden <noreply@getsentry.com>
+
+### Step 6: Output
+Return ONLY valid JSON (no surrounding text). Use `"status": "applied"` if you committed a fix, or `"status": "skipped"` if you did not.
+
+```json
+{
+  "status": "applied",
+  "filesChanged": ["src/example.ts"],
+  "testFilesChanged": ["src/example.test.ts"],
+  "selfReview": "Verified the fix addresses the null check and test covers the failure case",
+  "skipReason": null
+}
+```
+
+When skipping:
+```json
+{
+  "status": "skipped",
+  "filesChanged": [],
+  "testFilesChanged": [],
+  "selfReview": null,
+  "skipReason": "The suggested fix would introduce a regression in the error handling path"
+}
+```

.agents/skills/warden-sweep/references/patch-prompt.md

@@ -0,0 +1,25 @@
+Verify a code analysis finding. Determine if this is a TRUE issue or a FALSE POSITIVE.
+Do NOT write or edit any files. Research only.
+
+## Finding
+- Title: ${TITLE}
+- Severity: ${SEVERITY} | Confidence: ${CONFIDENCE}
+- Skill: ${SKILL}
+- Location: ${FILE_PATH}:${START_LINE}-${END_LINE}
+- Description: ${DESCRIPTION}
+- Verification hint: ${VERIFICATION}
+
+## Instructions
+1. Read the file at the reported location. Examine at least 50 lines of surrounding context.
+2. Trace data flow to/from the flagged code using Grep/Glob.
+3. Check if the issue is mitigated elsewhere (guards, validation, try/catch upstream).
+4. Check if the issue is actually reachable in practice.
+
+Return your verdict as JSON:
+{
+  "findingId": "${FINDING_ID}",
+  "verdict": "verified" or "rejected",
+  "confidence": "high" or "medium" or "low",
+  "reasoning": "2-3 sentence explanation",
+  "traceNotes": "What code paths you examined"
+}

.agents/skills/warden-sweep/references/verify-prompt.md

@@ -0,0 +1,99 @@
+"""Shared utilities for warden-sweep scripts."""
+from __future__ import annotations
+
+import json
+import os
+import subprocess
+from typing import Any
+
+
+def run_cmd(
+    args: list[str], timeout: int = 30, cwd: str | None = None
+) -> subprocess.CompletedProcess[str]:
+    """Run a command and return the result."""
+    return subprocess.run(
+        args,
+        capture_output=True,
+        text=True,
+        timeout=timeout,
+        cwd=cwd,
+    )
+
+
+def run_cmd_stdout(
+    args: list[str], timeout: int = 30, cwd: str | None = None
+) -> str | None:
+    """Run a command and return stripped stdout, or None on failure."""
+    try:
+        result = run_cmd(args, timeout=timeout, cwd=cwd)
+        return result.stdout.strip() if result.returncode == 0 else None
+    except (subprocess.TimeoutExpired, FileNotFoundError):
+        return None
+
+
+def read_json(path: str) -> dict[str, Any] | None:
+    """Read a JSON file and return parsed object, or None on failure."""
+    if not os.path.exists(path):
+        return None
+    try:
+        with open(path) as f:
+            return json.load(f)
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def write_json(path: str, data: dict[str, Any]) -> None:
+    """Write a dict to a JSON file with trailing newline."""
+    with open(path, "w") as f:
+        json.dump(data, f, indent=2)
+        f.write("\n")
+
+
+def read_jsonl(path: str) -> list[dict[str, Any]]:
+    """Read a JSONL file and return list of parsed objects."""
+    entries: list[dict[str, Any]] = []
+    if not os.path.exists(path):
+        return entries
+    with open(path) as f:
+        for line in f:
+            line = line.strip()
+            if not line:
+                continue
+            try:
+                entries.append(json.loads(line))
+            except json.JSONDecodeError:
+                continue
+    return entries
+
+
+def severity_badge(severity: str) -> str:
+    """Return a markdown-friendly severity indicator."""
+    badges = {
+        "critical": "**CRITICAL**",
+        "high": "**HIGH**",
+        "medium": "MEDIUM",
+        "low": "LOW",
+        "info": "info",
+    }
+    return badges.get(severity, severity)
+
+
+def pr_number_from_url(pr_url: str) -> str:
+    """Extract the PR or issue number from a GitHub URL's last path segment."""
+    return pr_url.rstrip("/").split("/")[-1]
+
+
+def ensure_github_label(name: str, color: str, description: str) -> None:
+    """Create a GitHub label if it doesn't exist (idempotent)."""
+    try:
+        subprocess.run(
+            [
+                "gh", "label", "create", name,
+                "--color", color,
+                "--description", description,
+            ],
+            capture_output=True,
+            timeout=15,
+        )
+    except (subprocess.TimeoutExpired, FileNotFoundError):
+        pass

.agents/skills/warden-sweep/scripts/_utils.py

@@ -0,0 +1,189 @@
+#!/usr/bin/env python3
+# /// script
+# requires-python = ">=3.9"
+# ///
+"""
+Warden Sweep: Create tracking issue.
+
+Creates a GitHub issue summarizing the sweep results after verification
+but before patching. Gives every PR a parent to reference and gives
+reviewers a single place to see the full picture.
+
+Usage:
+    uv run create_issue.py <sweep-dir>
+
+Stdout: JSON with issueUrl and issueNumber
+Stderr: Progress lines
+
+Idempotent: if issueUrl already exists in manifest, skips creation.
+"""
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import subprocess
+import sys
+from typing import Any
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+from _utils import (  # noqa: E402
+    ensure_github_label,
+    pr_number_from_url,
+    read_json,
+    read_jsonl,
+    severity_badge,
+    write_json,
+)
+
+
+def build_issue_body(
+    run_id: str,
+    scan_index: list[dict[str, Any]],
+    all_findings: list[dict[str, Any]],
+    verified: list[dict[str, Any]],
+    rejected: list[dict[str, Any]],
+) -> str:
+    """Build the GitHub issue body markdown."""
+    files_scanned = sum(1 for e in scan_index if e.get("status") == "complete")
+    files_timed_out = sum(
+        1 for e in scan_index
+        if e.get("status") == "error" and e.get("error") == "timeout"
+    )
+    files_errored = sum(
+        1 for e in scan_index
+        if e.get("status") == "error" and e.get("error") != "timeout"
+    )
+
+    # Collect unique skills from scan index
+    skills: set[str] = set()
+    for entry in scan_index:
+        for skill in entry.get("skills", []):
+            skills.add(skill)
+
+    lines = [
+        f"## Warden Sweep `{run_id}`",
+        "",
+        "| Metric | Count |",
+        "|--------|-------|",
+        f"| Files scanned | {files_scanned} |",
+        f"| Files timed out | {files_timed_out} |",
+        f"| Files errored | {files_errored} |",
+        f"| Total findings | {len(all_findings)} |",
+        f"| Verified | {len(verified)} |",
+        f"| Rejected | {len(rejected)} |",
+        "",
+    ]
+
+    if verified:
+        lines.append("### Verified Findings")
+        lines.append("")
+        lines.append("| Severity | Skill | File | Title |")
+        lines.append("|----------|-------|------|-------|")
+        for f in verified:
+            sev = severity_badge(f.get("severity", "info"))
+            skill = f.get("skill", "")
+            file_path = f.get("file", "")
+            start_line = f.get("startLine")
+            location = f"{file_path}:{start_line}" if start_line else file_path
+            title = f.get("title", "")
+            lines.append(f"| {sev} | {skill} | `{location}` | {title} |")
+        lines.append("")
+
+    if skills:
+        lines.append("### Skills Run")
+        lines.append("")
+        lines.append(", ".join(sorted(skills)))
+        lines.append("")
+
+    lines.append("> Generated by Warden Sweep. PRs referencing this issue will appear below.")
+
+    return "\n".join(lines) + "\n"
+
+
+def create_github_issue(title: str, body: str) -> dict[str, Any]:
+    """Create a GitHub issue with the warden label. Returns issueUrl and issueNumber."""
+    ensure_github_label("warden", "5319E7", "Automated fix from Warden Sweep")
+
+    result = subprocess.run(
+        [
+            "gh", "issue", "create",
+            "--label", "warden",
+            "--title", title,
+            "--body", body,
+        ],
+        capture_output=True,
+        text=True,
+        timeout=30,
+    )
+
+    if result.returncode != 0:
+        raise RuntimeError(f"gh issue create failed: {result.stderr.strip()}")
+
+    issue_url = result.stdout.strip()
+    try:
+        issue_number = int(pr_number_from_url(issue_url))
+    except (ValueError, IndexError):
+        raise RuntimeError(f"Could not parse issue number from gh output: {issue_url}")
+
+    return {"issueUrl": issue_url, "issueNumber": issue_number}
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Warden Sweep: Create tracking issue"
+    )
+    parser.add_argument("sweep_dir", help="Path to the sweep directory")
+    args = parser.parse_args()
+
+    sweep_dir = args.sweep_dir
+    data_dir = os.path.join(sweep_dir, "data")
+    manifest_path = os.path.join(data_dir, "manifest.json")
+
+    if not os.path.isdir(sweep_dir):
+        print(
+            json.dumps({"error": f"Sweep directory not found: {sweep_dir}"}),
+            file=sys.stdout,
+        )
+        sys.exit(1)
+
+    manifest = read_json(manifest_path) or {}
+
+    # Idempotency: if issue already exists, return existing values
+    if manifest.get("issueUrl"):
+        output = {
+            "issueUrl": manifest["issueUrl"],
+            "issueNumber": manifest.get("issueNumber", 0),
+        }
+        print(json.dumps(output))
+        return
+
+    run_id = manifest.get("runId", "unknown")
+
+    # Read sweep data
+    scan_index = read_jsonl(os.path.join(data_dir, "scan-index.jsonl"))
+    all_findings = read_jsonl(os.path.join(data_dir, "all-findings.jsonl"))
+    verified = read_jsonl(os.path.join(data_dir, "verified.jsonl"))
+    rejected = read_jsonl(os.path.join(data_dir, "rejected.jsonl"))
+
+    files_scanned = sum(1 for e in scan_index if e.get("status") == "complete")
+
+    # Build issue
+    title = f"Warden Sweep {run_id}: {len(verified)} findings across {files_scanned} files"
+    body = build_issue_body(run_id, scan_index, all_findings, verified, rejected)
+
+    print("Creating tracking issue...", file=sys.stderr)
+    result = create_github_issue(title, body)
+    print(f"Created issue: {result['issueUrl']}", file=sys.stderr)
+
+    # Write issueUrl and issueNumber to manifest
+    manifest["issueUrl"] = result["issueUrl"]
+    manifest["issueNumber"] = result["issueNumber"]
+    manifest.setdefault("phases", {})["issue"] = "complete"
+    write_json(manifest_path, manifest)
+
+    print(json.dumps(result))
+
+
+if __name__ == "__main__":
+    main()