refactor(git-service): rename GitServiceImpl → GitService

No interface exists for the class, so the Impl suffix is vestigial
Java-style naming. Rename throughout: git-service.js, auto-start.js,
auto.js, worktree.js, worktree-detect.js, worktree-resolver.js,
quick.js, and the two test files that imported it directly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

ARCHITECTURE.md

@@ -96,13 +96,64 @@ stateDiagram-v2
     PhaseComplete --> PhaseExecute : remediation milestone added
 
     note right of PhaseExecute
-        Task lifecycle (ORCH-style):
+        See Task Lifecycle diagram below.
-        todo → running → verifying → reviewing
-             → done | blocked | paused | failed
-             | cancelled | retrying
     end note
 ```
 
+```mermaid
+stateDiagram-v2
+    direction TB
+
+    [*] --> todo : task created
+
+    todo --> running : dispatch picks task
+    todo --> cancelled : explicit cancel
+
+    running --> verifying : implementation done, run checks
+    running --> reviewing : needs human / agent review
+    running --> done : trivial task, skip verify
+    running --> blocked : dependency unresolved
+    running --> paused : user interrupt
+    running --> retrying : transient failure, retry
+    running --> failed : unrecoverable error
+    running --> cancelled : explicit cancel
+
+    verifying --> reviewing : checks pass, review needed
+    verifying --> done : checks pass, no review needed
+    verifying --> blocked : check dependency missing
+    verifying --> paused : user interrupt
+    verifying --> retrying : check flake, retry
+    verifying --> failed : checks failed
+    verifying --> cancelled : explicit cancel
+
+    reviewing --> running : feedback applied, re-implement
+    reviewing --> verifying : back to verify after edits
+    reviewing --> done : review approved
+    reviewing --> blocked : waiting on reviewer
+    reviewing --> paused : user interrupt
+    reviewing --> failed : review rejected
+    reviewing --> cancelled : explicit cancel
+
+    blocked --> todo : dependency resolved, reset
+    blocked --> running : unblocked, resume
+    blocked --> retrying : auto-unblock retry
+    blocked --> cancelled : explicit cancel
+
+    paused --> running : resume
+    paused --> retrying : auto-resume
+    paused --> cancelled : explicit cancel
+
+    retrying --> running : retry attempt starts
+    retrying --> failed : retry budget exhausted
+    retrying --> cancelled : explicit cancel
+
+    failed --> retrying : manual re-queue
+    failed --> cancelled : give up
+
+    done --> [*]
+    cancelled --> [*]
+```
+
 ```mermaid
 stateDiagram-v2
     direction LR

src/resources/extensions/sf/auto-start.js

@@ -39,7 +39,7 @@ import {
 	setLevelChangeCallback,
 } from "./doctor-proactive.js";
 import { getManifestStatus, loadFile } from "./files.js";
-import { GitServiceImpl } from "./git-service.js";
+import { GitService } from "./git-service.js";
 import { ensureGitignore, untrackRuntimeFiles } from "./gitignore.js";
 import { initMetrics } from "./metrics.js";
 import { initMetricsCentral } from "./metrics-central.js";
@@ -474,8 +474,8 @@ export async function bootstrapAutoSession(
 				);
 			}
 		}
-		// Initialize GitServiceImpl
+		// Initialize GitService
-		s.gitService = new GitServiceImpl(
+		s.gitService = new GitService(
 			s.basePath,
 			loadEffectiveSFPreferences()?.preferences?.git ?? {},
 		);

src/resources/extensions/sf/auto.js

@@ -121,7 +121,7 @@ import {
 	setLevelChangeCallback,
 } from "./doctor-proactive.js";
 import { getErrorMessage } from "./error-utils.js";
-import { GitServiceImpl } from "./git-service.js";
+import { GitService } from "./git-service.js";
 import { initHealthWidget } from "./health-widget.js";
 import { emitJournalEvent as _emitJournalEvent } from "./journal.js";
 import {
@@ -1304,7 +1304,7 @@ function buildResolverDeps() {
 		autoWorktreeBranch,
 		resolveMilestoneFile,
 		readFileSync: (path, encoding) => readFileSync(path, encoding),
-		GitServiceImpl: GitServiceImpl,
+		GitService: GitService,
 		loadEffectiveSFPreferences: loadEffectiveSFPreferences,
 		invalidateAllCaches,
 		captureIntegrationBranch,
@@ -1406,7 +1406,7 @@ function buildLoopDeps() {
 		readFileSync: (path, encoding) => readFileSync(path, encoding),
 		atomicWriteSync,
 		// Git
-		GitServiceImpl: GitServiceImpl,
+		GitService: GitService,
 		// WorktreeResolver
 		resolver: buildResolver(),
 		// Post-unit processing

src/resources/extensions/sf/git-service.js

@@ -374,8 +374,8 @@ const COMMIT_TYPE_RULES = [
 		"chore",
 	],
 ];
-// ─── GitServiceImpl ────────────────────────────────────────────────────
+// ─── GitService ────────────────────────────────────────────────────
-export class GitServiceImpl {
+export class GitService {
 	basePath;
 	prefs;
 	/** Active milestone ID — used to resolve the integration branch. */
@@ -766,10 +766,10 @@ export function createDraftPR(basePath, _milestoneId, title, body, opts) {
 	}
 }
 // ─── Factory ───────────────────────────────────────────────────────────────
-/** Create a GitServiceImpl with the current effective git preferences. */
+/** Create a GitService with the current effective git preferences. */
 export function createGitService(basePath) {
 	const gitPrefs = loadEffectiveSFPreferences()?.preferences?.git ?? {};
-	return new GitServiceImpl(basePath, gitPrefs);
+	return new GitService(basePath, gitPrefs);
 }
 function buildTurnSnapshotLabel(unitType, unitId) {
 	const raw = `${unitType}/${unitId}`.trim();

src/resources/extensions/sf/quick.js

@@ -17,7 +17,7 @@ import {
 	writeFileSync,
 } from "node:fs";
 import { join } from "node:path";
-import { GitServiceImpl, runGit } from "./git-service.js";
+import { GitService, runGit } from "./git-service.js";
 import { nativeHasStagedChanges } from "./native-git-bridge.js";
 import { sfRoot } from "./paths.js";
 import { loadEffectiveSFPreferences } from "./preferences.js";
@@ -117,7 +117,7 @@ export function cleanupQuickBranch(basePath = process.cwd()) {
 	if (!state) return false;
 	const repoPath = state.basePath;
 	const gitPrefs = loadEffectiveSFPreferences()?.preferences?.git ?? {};
-	const git = new GitServiceImpl(repoPath, gitPrefs);
+	const git = new GitService(repoPath, gitPrefs);
 	if (git.getCurrentBranch() === state.quickBranch) {
 		try {
 			git.autoCommit("quick-task", `Q${state.taskNum}`, []);
@@ -170,7 +170,7 @@ export async function handleQuick(args, ctx, pi) {
 	const date = new Date().toISOString().split("T")[0];
 	// Create git branch for the quick task (unless isolation:none — #3337)
 	const gitPrefs = loadEffectiveSFPreferences()?.preferences?.git ?? {};
-	const git = new GitServiceImpl(basePath, gitPrefs);
+	const git = new GitService(basePath, gitPrefs);
 	const branchName = `sf/quick/${taskNum}-${slug}`;
 	const originalBranch = git.getCurrentBranch();
 	const { getIsolationMode } = await import("./preferences.js");

src/resources/extensions/sf/tests/auto-post-unit-staging.test.mjs

@@ -49,8 +49,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			writeFileSync(join(base, "src/index.ts"), "export {}");
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			git.stageExplicitIncludePaths(["src/index.ts"], []);
 
 			expect(nativeAddPathsMock).toHaveBeenCalledOnce();
@@ -68,8 +68,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			writeFileSync(join(base, ".sf", "plans", "foo.md"), "# plan");
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			git.stageExplicitIncludePaths([".sf/plans/foo.md"], []);
 
 			expect(nativeAddPathsMock).not.toHaveBeenCalled();
@@ -89,8 +89,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			);
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			git.stageExplicitIncludePaths([".sf/milestones/M001/SLICE.md"], []);
 
 			expect(nativeAddPathsMock).not.toHaveBeenCalled();
@@ -109,8 +109,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			writeFileSync(join(base, ".sf", "plans", "foo.md"), "# plan");
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			git.stageExplicitIncludePaths([".sf/plans/foo.md", "src/index.ts"], []);
 
 			expect(nativeAddPathsMock).toHaveBeenCalledOnce();
@@ -126,8 +126,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			mkdirSync(join(base, ".git"), { recursive: true });
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			// Windows-style: .sf\plans\foo.md → normalized to .sf/plans/foo.md
 			// First segment is .sf → should be filtered
 			git.stageExplicitIncludePaths([".sf\\plans\\foo.md"], []);
@@ -146,8 +146,8 @@ describe("stageExplicitIncludePaths .sf/ filter", () => {
 			writeFileSync(join(base, "foo", ".sf", "plans", "foo.md"), "# plan");
 
 			nativeAddPathsMock.mockClear();
-			const { GitServiceImpl } = await import("../git-service.js");
+			const { GitService } = await import("../git-service.js");
-			const git = new GitServiceImpl(base);
+			const git = new GitService(base);
 			// foo\.sf\... → normalized to foo/.sf/... → first segment = foo → NOT filtered
 			// (this is a subdirectory named .sf under foo/, not the SF state dir)
 			git.stageExplicitIncludePaths(["foo\\.sf\\plans\\foo.md"], []);

src/resources/extensions/sf/tests/worktree-fixes.test.mjs

@@ -232,7 +232,7 @@ describe("WorktreeResolver.enterMilestone", () => {
 			getAutoWorktreePath: () => "/project/.sf/worktrees/M001",
 			enterAutoWorktree: () => "/project/.sf/worktrees/M001",
 			createAutoWorktree: () => "/project/.sf/worktrees/M001",
-			GitServiceImpl: class MockGitService {},
+			GitService: class MockGitService {},
 			loadEffectiveSFPreferences: () => ({}),
 			invalidateAllCaches: () => {},
 		};

src/resources/extensions/sf/worktree-detect.js

@@ -3,7 +3,7 @@
  *
  * Extracted from worktree.js so that git-service.js can import
  * detectWorktreeName without pulling in the full worktree module
- * (which in turn imports GitServiceImpl from git-service.js, creating
+ * (which in turn imports GitService from git-service.js, creating
  * a cycle).  worktree.js re-exports both symbols for back-compat.
  *
  * Purpose: provide a zero-dependency path for detecting whether a
@@ -40,7 +40,7 @@ function findWorktreeSegment(normalizedPath) {
  * Detect the active worktree name from the current working directory.
  * Returns null if not inside a SF worktree (.sf/worktrees/<name>/).
  *
- * Consumer: git-service.js (GitServiceImpl.getTargetBranch) and worktree.js.
+ * Consumer: git-service.js (GitService.getTargetBranch) and worktree.js.
  *
  * @param {string} basePath
  * @returns {string | null}

src/resources/extensions/sf/worktree-resolver.js

@@ -58,7 +58,7 @@ export class WorktreeResolver {
 	rebuildGitService() {
 		const gitConfig =
 			this.deps.loadEffectiveSFPreferences()?.preferences?.git ?? {};
-		this.s.gitService = new this.deps.GitServiceImpl(
+		this.s.gitService = new this.deps.GitService(
 			this.s.basePath,
 			gitConfig,
 		);

src/resources/extensions/sf/worktree.js

@@ -14,7 +14,7 @@
 import { existsSync, readFileSync, realpathSync, utimesSync } from "node:fs";
 import { homedir } from "node:os";
 import { join, resolve } from "node:path";
-import { GitServiceImpl, writeIntegrationBranch } from "./git-service.js";
+import { GitService, writeIntegrationBranch } from "./git-service.js";
 import { loadEffectiveSFPreferences } from "./preferences.js";
 import { detectWorktreeName, findWorktreeSegment } from "./worktree-detect.js";
 
@@ -22,11 +22,11 @@ export { MergeConflictError } from "./git-service.js";
 // Re-export for consumers that import detectWorktreeName from ./worktree.js
 export { detectWorktreeName } from "./worktree-detect.js";
 
-// ─── Lazy GitServiceImpl Cache ─────────────────────────────────────────────
+// ─── Lazy GitService Cache ─────────────────────────────────────────────
 let cachedService = null;
 let cachedBasePath = null;
 /**
- * Get or create a GitServiceImpl for the given basePath.
+ * Get or create a GitService for the given basePath.
  * Resets the cache if basePath changes between calls.
  * Lazy construction: only instantiated at call-time, never at module-evaluation.
  */
@@ -34,13 +34,13 @@ function getService(basePath) {
 	if (cachedService === null || cachedBasePath !== basePath) {
 		const loaded = loadEffectiveSFPreferences();
 		const gitPrefs = loaded?.preferences?.git ?? {};
-		cachedService = new GitServiceImpl(basePath, gitPrefs);
+		cachedService = new GitService(basePath, gitPrefs);
 		cachedBasePath = basePath;
 	}
 	return cachedService;
 }
 /**
- * Clear the cached GitServiceImpl. For testing only — forces the next
+ * Clear the cached GitService. For testing only — forces the next
  * getService() call to re-read preferences and create a fresh instance.
  * @internal
  */
@@ -49,7 +49,7 @@ export function _resetServiceCache() {
 	cachedBasePath = null;
 }
 /**
- * Set the active milestone ID on the cached GitServiceImpl.
+ * Set the active milestone ID on the cached GitService.
  * This enables integration branch resolution in getMainBranch().
  */
 export function setActiveMilestoneId(basePath, milestoneId) {
@@ -215,7 +215,7 @@ export function parseSliceBranch(branchName) {
 		sliceId: match[3],
 	};
 }
-// ─── Git-Mutation Functions (delegate to GitServiceImpl) ───────────────────
+// ─── Git-Mutation Functions (delegate to GitService) ───────────────────
 /**
  * Get the "main" branch for SF slice operations.
  *