feat(code-review): integrate fallow structural pre-pass for /gsd-code-review (#3424)

* feat(code-review): add optional fallow structural pre-pass

* fix(ci): sync lockfile for fallow optional binaries

* fix(test): make fallow integration tests cross-platform

* fix(review): require executable fallow binary paths

* docs(review): clarify structural findings usage and size guard

* fix(fallow): preserve line:0, prefer node_modules/.bin, sync SDK twin (H1, M2, N1 from #3424 review)

* fix(workflow): harden fallow pre-pass — exit check, timeout, atomic write, size-guard order (B1, H2-H4, M1, M3 from #3424 review)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(deps): pin fallow floor to ^2.70.0 matching lockfile (H7 from #3424 review)

* fix(config): enum-validate fallow.scope/profile + group code_quality.* contiguously (H5, N3 from #3424 review)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* docs(fallow): label mcp gate reserved, version-pin install, expand context schema (B3, H8, M4, M8, L1 from #3424 review)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* test(fallow): replace source-grep with behavioral tests, expand fixtures, fail-loud tmpdir (B4, H6, L2, L3, M5, M6, N2 from #3424 review)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(workflow): escape closing structural_findings tag in JSON payload (CR #3424 inline finding)

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/CONFIGURATION.md

@@ -59,6 +59,14 @@ GSD stores project settings in `.planning/config.json`. Created during `/gsd-new
     "build_command": null,
     "test_command": null
   },
+  "code_quality": {
+    "fallow": {
+      "enabled": false,
+      "scope": "phase",
+      "profile": "standard",
+      "mcp": false
+    }
+  },
   "ship": {
     "pr_body_sections": []
   },
@@ -250,6 +258,17 @@ All workflow toggles follow the **absent = enabled** pattern. If a key is missin
 | `workflow.build_command` | string | (none) | Shell command to build the project in the post-merge build gate (Step A of step 5.6 in execute-phase). When unset, the gate auto-detects: Xcode (`.xcodeproj` present) → `xcodebuild build`, `Makefile` with `build:` target → `make build`, Justfile → `just build`, `Cargo.toml` → `cargo build`, `go.mod` → `go build ./...`, Python → `python -m py_compile`, `package.json` with `build` script → `npm run build`. Runs with a 5-minute timeout; failure increments `WAVE_FAILURE_COUNT`. Added in v1.39 |
 | `workflow.test_command` | string | (none) | Shell command to run the project's test suite in the post-merge test gate (Step B of step 5.6 in execute-phase) and the regression gate. When unset, the gate auto-detects: Xcode (`.xcodeproj` present) → `xcodebuild test`, `Makefile` with `test:` target → `make test`, Justfile → `just test`, `package.json` → `npm test`, `Cargo.toml` → `cargo test`, `go.mod` → `go test ./...`, Python → `python -m pytest`. Runs with a 5-minute timeout; failure increments `WAVE_FAILURE_COUNT`. Added in v1.39 |
 
+## Code Quality Settings
+
+The `code_quality.*` namespace gates optional structural-analysis tooling that augments `/gsd-code-review`. Settings are additive: each tool is independently opt-in and off by default.
+
+| Setting | Type | Default | Description |
+|---------|------|---------|-------------|
+| `code_quality.fallow.enabled` | boolean | `false` | Enables fallow structural pre-pass for `/gsd-code-review`. When `false`, no fallow binary probe or JSON artifact is produced. |
+| `code_quality.fallow.scope` | string | `phase` | Scope for fallow analysis: `phase` (current review file scope) or `repo` (entire repository). |
+| `code_quality.fallow.profile` | string | `standard` | Fallow profile selector passed to the pre-pass runner (`minimal`, `standard`, `strict`). |
+| `code_quality.fallow.mcp` | boolean | `false` | **Reserved — not yet implemented.** When `true`, enables MCP-backed structural findings mode for runtimes that support MCP server routing. Setting this to `true` is currently a no-op and emits a runtime warning. |
+
 ## Ship Settings
 
 `ship.pr_body_sections` adds additional PR body sections for project-specific PRD/PR body content in `/gsd-ship` without editing `get-shit-done/workflows/ship.md`.

docs/INVENTORY-MANIFEST.json

@@ -273,6 +273,7 @@
       "decisions.cjs",
       "docs.cjs",
       "drift.cjs",
+      "fallow-runner.cjs",
       "frontmatter.cjs",
       "gap-checker.cjs",
       "graphify.cjs",

docs/INVENTORY.md

@@ -360,7 +360,7 @@ The `gsd-planner` agent is decomposed into a core agent plus reference modules t
 
 ---
 
-## CLI Modules (58 shipped)
+## CLI Modules (59 shipped)
 
 Full listing: `get-shit-done/bin/lib/*.cjs`.
 
@@ -381,6 +381,7 @@ Full listing: `get-shit-done/bin/lib/*.cjs`.
 | `decisions.cjs` | Shared parser for CONTEXT.md `<decisions>` blocks (D-NN entries); used by `gap-checker.cjs` and intended for #2492 plan/verify decision gates |
 | `docs.cjs` | Docs-update workflow init, Markdown scanning, monorepo detection |
 | `drift.cjs` | Post-execute codebase structural drift detector (#2003): classifies file changes into new-dir/barrel/migration/route categories and round-trips `last_mapped_commit` frontmatter |
+| `fallow-runner.cjs` | Fallow audit adapter for `/gsd-code-review`: binary resolution (`PATH` then `node_modules/.bin`), actionable missing-binary errors, and structural findings normalization |
 | `frontmatter.cjs` | YAML frontmatter CRUD operations |
 | `gap-checker.cjs` | Post-planning gap analysis (#2493): unified REQUIREMENTS.md + CONTEXT.md decisions vs PLAN.md coverage report (`gsd-tools gap-analysis`) |
 | `graphify.cjs` | Knowledge-graph build/query/status/diff for `/gsd-graphify` |