Move the code and terraform audits into the reviews plugin

Copy the standalone code-review and terraform-review skills into
plugins/reviews as audit-code and audit-terraform. The rename separates the
automated, linter-driven audits from the guided review-pr walkthrough that
already lived here.

Resolve bundled script paths through ${SKILL_DIR}, exported in a new step 0.
CLAUDE_PLUGIN_ROOT is not set in the Bash tool environment, so the obvious
substitution would have expanded to nothing and broken every collection
script invocation.

Replace the PLAN and DESIGN docs with READMEs written from the current
SKILL.md and scripts. The old docs had drifted badly: they named semgrep
where the code calls opengrep, scoped five review agents where there are
now eight, and predated Lua, PowerShell, and GitHub Actions support.

Add CONSISTENCY_NORMS to the audit-terraform agent inputs. The collection
script writes consistency_norms.json and the agent prompt declares it, but
SKILL.md never listed it, leaving the variable unsubstituted.

Drop the --ingest-verdicts instruction from both skills. review_stats.py
parses no arguments, so the ref-mode verdict template it told users to feed
back could never be read.

Point audit-terraform's smoke test at README.md and resolve its fixture
paths relative to the test file rather than an absolute home directory.

Tests: 197 passing (audit-code), 106 passing (audit-terraform).

plugins/reviews/skills/audit-terraform/scripts/reference_set.py

@@ -0,0 +1,146 @@
+"""Compute reference sets for the consistency reviewer."""
+from __future__ import annotations
+
+import re
+from collections import Counter, defaultdict
+from pathlib import Path
+
+from scripts.manifest import ModuleGraphEntry
+
+
+def _peer_dirs_at_depth(repo_root: Path, dir_path: str) -> list[str]:
+    parts = dir_path.split("/")
+    depth = len(parts)
+    parent = repo_root.joinpath(*parts[:-1]) if depth > 1 else repo_root
+    if not parent.is_dir():
+        return []
+    out: list[str] = []
+    for p in sorted(parent.iterdir()):
+        if not p.is_dir():
+            continue
+        rel = p.relative_to(repo_root).as_posix()
+        if rel != dir_path:
+            out.append(rel)
+    return out
+
+
+def _terragrunt_refs(repo_root: Path, dir_path: str) -> list[str]:
+    """Region peers + same-component cross-env (layout: live/<env>/<region>/<component>)."""
+    parts = dir_path.split("/")
+    if len(parts) != 4:
+        return _peer_dirs_at_depth(repo_root, dir_path)
+    live, env, region, component = parts
+    refs: set[str] = set()
+    region_dir = repo_root / live / env / region
+    if region_dir.is_dir():
+        for p in region_dir.iterdir():
+            if p.is_dir() and (p / "terragrunt.hcl").is_file():
+                rel = p.relative_to(repo_root).as_posix()
+                if rel != dir_path:
+                    refs.add(rel)
+    live_dir = repo_root / live
+    if live_dir.is_dir():
+        for env_dir in live_dir.iterdir():
+            candidate = env_dir / region / component
+            if candidate.is_dir() and (candidate / "terragrunt.hcl").is_file():
+                rel = candidate.relative_to(repo_root).as_posix()
+                if rel != dir_path:
+                    refs.add(rel)
+    env_live_dir = repo_root / live / env
+    if env_live_dir.is_dir():
+        for region_dir2 in env_live_dir.iterdir():
+            candidate = region_dir2 / component
+            if candidate.is_dir() and (candidate / "terragrunt.hcl").is_file():
+                rel = candidate.relative_to(repo_root).as_posix()
+                if rel != dir_path:
+                    refs.add(rel)
+    return sorted(refs)
+
+
+def compute_reference_sets(
+    repo_root: Path | str,
+    changed_dirs: set[str],
+    module_graph: dict[str, ModuleGraphEntry],
+) -> dict[str, list[str]]:
+    root = Path(repo_root)
+    out: dict[str, list[str]] = {}
+    for d in sorted(changed_dirs):
+        if d.startswith("modules/"):
+            entry = module_graph.get(d)
+            out[d] = list(entry.sibling_modules_at_callsites) if entry else []
+            continue
+        full = root / d
+        if (full / "terragrunt.hcl").is_file():
+            out[d] = _terragrunt_refs(root, d)
+            continue
+        out[d] = _peer_dirs_at_depth(root, d)
+    return out
+
+
+_ATTR_RE = re.compile(r"^\s*(?P<key>[A-Za-z0-9_]+)\s*=")
+_MODULE_RE = re.compile(r'^\s*module\s+"(?P<name>[^"]+)"\s*\{')
+
+
+def _iter_tf_lines(dir_path: Path) -> list[str]:
+    lines: list[str] = []
+    for tf in sorted(dir_path.glob("*.tf")):
+        lines.extend(tf.read_text().splitlines())
+    return lines
+
+
+def _dir_signature(dir_path: Path) -> tuple[set[str], set[str]]:
+    attrs: set[str] = set()
+    modules: set[str] = set()
+    for line in _iter_tf_lines(dir_path):
+        attr_match = _ATTR_RE.match(line)
+        if attr_match:
+            attrs.add(attr_match.group("key"))
+        module_match = _MODULE_RE.match(line)
+        if module_match:
+            modules.add(module_match.group("name"))
+    return attrs, modules
+
+
+def compute_consistency_norms(
+    repo_root: Path | str,
+    reference_sets: dict[str, list[str]],
+) -> dict[str, dict[str, list[dict[str, object]]]]:
+    root = Path(repo_root)
+    out: dict[str, dict[str, list[dict[str, object]]]] = {}
+    for changed_dir, refs in sorted(reference_sets.items()):
+        attr_support: dict[str, list[str]] = defaultdict(list)
+        module_support: dict[str, list[str]] = defaultdict(list)
+        naming_tokens: Counter[str] = Counter()
+        usable_refs: list[str] = []
+        for ref in refs:
+            ref_path = root / ref
+            if not ref_path.is_dir():
+                continue
+            attrs, modules = _dir_signature(ref_path)
+            if not attrs and not modules:
+                continue
+            usable_refs.append(ref)
+            for attr in attrs:
+                attr_support[attr].append(ref)
+            for module in modules:
+                module_support[module].append(ref)
+            naming_tokens.update(Path(ref).parts[-1:])
+
+        out[changed_dir] = {
+            "attribute_norms": [
+                {"attribute": attr, "peer_dirs": sorted(peer_dirs)}
+                for attr, peer_dirs in sorted(attr_support.items())
+                if len(peer_dirs) >= 2
+            ],
+            "module_wrapper_norms": [
+                {"module": module, "peer_dirs": sorted(peer_dirs)}
+                for module, peer_dirs in sorted(module_support.items())
+                if len(peer_dirs) >= 2
+            ],
+            "naming_norms": [
+                {"token": token, "peer_dirs": sorted(usable_refs)}
+                for token, count in sorted(naming_tokens.items())
+                if count >= 2
+            ],
+        }
+    return out