Migrate review to skill-based architecture

- Review methodology lives in factory-plugins core plugin (code-review skill)
- CI loads shared methodology from plugin cache at runtime
- Skill uses BEGIN/END_SHARED_METHODOLOGY markers to separate:
  - Shared: bug patterns, analysis discipline, reporting gate, priorities, format
  - Shallow (TUI): local context detection + local findings output
  - Deep (CI): pre-computed artifacts, MCP tools, posting, validator flow
- CI always posts comments (deep flow); TUI skill returns locally (shallow flow)
- formatSkillSection extracts only shared methodology for CI prompt injection

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

Author: factory-nizar

src/utils/load-skill.ts

@@ -0,0 +1,71 @@
+import { readFile, readdir } from "fs/promises";
+import { resolve, join } from "path";
+
+const SHARED_BEGIN = "<!-- BEGIN_SHARED_METHODOLOGY -->";
+const SHARED_END = "<!-- END_SHARED_METHODOLOGY -->";
+
+/**
+ * Format skill content for inclusion in a CI prompt.
+ * Extracts only the shared methodology (between markers) so deep-specific
+ * instructions in the CI template are authoritative for execution behavior.
+ */
+export function formatSkillSection(skillContent: string | undefined): string {
+  if (!skillContent) return "";
+  const methodology = extractSharedMethodology(skillContent);
+  return `
+<code_review_methodology>
+${methodology}
+</code_review_methodology>
+`;
+}
+
+/**
+ * Extract the shared methodology section from a skill's content.
+ * Looks for BEGIN_SHARED_METHODOLOGY / END_SHARED_METHODOLOGY markers.
+ * Returns the full content if markers are not found.
+ */
+export function extractSharedMethodology(content: string): string {
+  const beginIdx = content.indexOf(SHARED_BEGIN);
+  const endIdx = content.indexOf(SHARED_END);
+  if (beginIdx === -1 || endIdx === -1 || endIdx <= beginIdx) {
+    return content;
+  }
+  return content.slice(beginIdx + SHARED_BEGIN.length, endIdx).trim();
+}
+
+/**
+ * Load a skill from the core plugin cache.
+ * The Droid CLI installs the core plugin to:
+ *   ~/.factory/plugins/cache/factory-plugins/core/<hash>/skills/<name>/SKILL.md
+ */
+export async function loadSkill(
+  skillName: string,
+): Promise<string | undefined> {
+  const home = process.env.HOME || "~";
+  const cacheDir = resolve(home, ".factory/plugins/cache/factory-plugins/core");
+
+  try {
+    const entries = await readdir(cacheDir);
+    for (const hash of entries) {
+      const skillPath = join(cacheDir, hash, "skills", skillName, "SKILL.md");
+      try {
+        const content = await readFile(skillPath, "utf8");
+        const trimmed = content.trim();
+        if (!trimmed) continue;
+        console.log(
+          `Loaded skill ${skillName} from ${skillPath} (${trimmed.length} bytes)`,
+        );
+        return trimmed;
+      } catch {
+        continue;
+      }
+    }
+  } catch {
+    // Cache dir doesn't exist
+  }
+
+  console.log(
+    `Skill ${skillName} not found in core plugin cache. Ensure the Droid CLI is installed.`,
+  );
+  return undefined;
+}

test/integration/review-flow.test.ts

@@ -8,6 +8,7 @@ import * as createInitial from "../../src/github/operations/comments/create-init
 import * as mcpInstaller from "../../src/mcp/install-mcp-server";
 import * as actorValidation from "../../src/github/validation/actor";
 import * as promptModule from "../../src/create-prompt";
+import * as skillLoader from "../../src/utils/load-skill";
 import * as core from "@actions/core";
 import * as childProcess from "node:child_process";
 
@@ -23,6 +24,7 @@ describe("review command integration", () => {
   let exportVarSpy: ReturnType<typeof spyOn>;
   let promptSpy: ReturnType<typeof spyOn>;
   let execSyncSpy: ReturnType<typeof spyOn>;
+  let loadSkillSpy: ReturnType<typeof spyOn>;
 
   beforeEach(async () => {
     tmpDir = await mkdtemp(path.join(os.tmpdir(), "review-int-"));
@@ -39,6 +41,7 @@ describe("review command integration", () => {
     promptSpy = spyOn(promptModule, "createPrompt").mockResolvedValue();
     setOutputSpy = spyOn(core, "setOutput").mockImplementation(() => {});
     exportVarSpy = spyOn(core, "exportVariable").mockImplementation(() => {});
+    loadSkillSpy = spyOn(skillLoader, "loadSkill").mockResolvedValue(undefined);
 
     execSyncSpy = spyOn(childProcess, "execSync").mockImplementation(((
       cmd: string,
@@ -60,6 +63,7 @@ describe("review command integration", () => {
     setOutputSpy.mockRestore();
     exportVarSpy.mockRestore();
     execSyncSpy.mockRestore();
+    loadSkillSpy.mockRestore();
 
     if (process.env.RUNNER_TEMP) {
       await rm(process.env.RUNNER_TEMP, { recursive: true, force: true });

test/modes/tag/review-command.test.ts

@@ -6,6 +6,7 @@ import { createMockContext } from "../../mockContext";
 import * as promptModule from "../../../src/create-prompt";
 import * as mcpInstaller from "../../../src/mcp/install-mcp-server";
 import * as comments from "../../../src/github/operations/comments/create-initial";
+import * as skillLoader from "../../../src/utils/load-skill";
 import * as childProcess from "child_process";
 import * as fsPromises from "fs/promises";
 
@@ -39,6 +40,7 @@ describe("prepareReviewMode", () => {
   let execSyncSpy: ReturnType<typeof spyOn>;
   let writeFileSpy: ReturnType<typeof spyOn>;
   let mkdirSpy: ReturnType<typeof spyOn>;
+  let loadSkillSpy: ReturnType<typeof spyOn>;
 
   beforeEach(() => {
     process.env.DROID_ARGS = "";
@@ -57,6 +59,7 @@ describe("prepareReviewMode", () => {
     exportVariableSpy = spyOn(core, "exportVariable").mockImplementation(
       () => {},
     );
+    loadSkillSpy = spyOn(skillLoader, "loadSkill").mockResolvedValue(undefined);
     // Mock execSync for git commands
     execSyncSpy = spyOn(childProcess, "execSync").mockImplementation(((
       cmd: string,
@@ -84,6 +87,7 @@ describe("prepareReviewMode", () => {
     execSyncSpy.mockRestore();
     writeFileSpy.mockRestore();
     mkdirSpy.mockRestore();
+    loadSkillSpy.mockRestore();
     process.env.DROID_ARGS = originalArgs;
     if (originalReviewModel !== undefined) {
       process.env.REVIEW_MODEL = originalReviewModel;