refactor(desktop): assert git-ipc surface by invariant, drop channel snapshot

electron/main.cjs is the worst god file in the desktop app (~7.6k lines, 93 IPC
handlers across unrelated domains). Begin peeling cohesive handler clusters into
sibling modules — the established main.cjs pattern.

First cluster: the 19 git/worktree/review IPC handlers (all thin delegators to
the existing git-*-ops modules) move into a new electron/git-ipc.cjs exposing
registerGitIpc({ ipcMain, resolveGitBinary, resolveGhBinary }). The git/gh
binary resolvers stay in main.cjs (Windows PATH discovery) and are injected, so
the new module is pure. Channel names are unchanged, so preload/renderer are
unaffected.

Adds electron/git-ipc.test.cjs (wired into test:desktop:platforms) asserting
the full channel surface and resolver delegation. main.cjs: 7,617 -> 7,530.

apps/desktop/electron/git-ipc.cjs

@@ -0,0 +1,96 @@
+'use strict'
+
+const { scanGitRepos } = require('./git-repo-scan.cjs')
+const {
+  fileDiffVsHead,
+  repoStatus,
+  reviewCommit,
+  reviewCommitContext,
+  reviewCreatePr,
+  reviewDiff,
+  reviewList,
+  reviewPush,
+  reviewRevParse,
+  reviewRevert,
+  reviewShipInfo,
+  reviewStage,
+  reviewUnstage
+} = require('./git-review-ops.cjs')
+const { addWorktree, listBranches, listWorktrees, removeWorktree, switchBranch } = require('./git-worktree-ops.cjs')
+
+// Register the git/worktree/review IPC handlers. Thin delegators to the
+// git-*-ops sibling modules; the git/gh binary resolution lives in the main
+// process (Windows PATH discovery) and is injected so this module stays pure.
+function registerGitIpc({ ipcMain, resolveGitBinary, resolveGhBinary }) {
+  // Git-driven worktree management ("Start work" flow). Errors surface to the
+  // renderer as rejected promises so it can toast a friendly message.
+  ipcMain.handle('hermes:git:worktreeList', async (_event, repoPath) => listWorktrees(repoPath, resolveGitBinary()))
+
+  ipcMain.handle('hermes:git:worktreeAdd', async (_event, repoPath, options) =>
+    addWorktree(repoPath, options || {}, resolveGitBinary())
+  )
+
+  ipcMain.handle('hermes:git:worktreeRemove', async (_event, repoPath, worktreePath, options) =>
+    removeWorktree(repoPath, worktreePath, options || {}, resolveGitBinary())
+  )
+
+  ipcMain.handle('hermes:git:branchSwitch', async (_event, repoPath, branch) =>
+    switchBranch(repoPath, branch, resolveGitBinary())
+  )
+
+  ipcMain.handle('hermes:git:branchList', async (_event, repoPath) => listBranches(repoPath, resolveGitBinary()))
+
+  // Compact repo status (branch, ahead/behind, change counts + files) for the
+  // composer coding rail. Returns null on a non-repo / remote backend so the rail
+  // hides cleanly rather than erroring.
+  ipcMain.handle('hermes:git:repoStatus', async (_event, repoPath) => repoStatus(repoPath, resolveGitBinary()))
+
+  // Codex-style review pane: list changed files for a scope, fetch one file's
+  // unified diff, and stage / unstage / revert. Reads return empty on failure;
+  // mutations reject so the renderer can toast.
+  ipcMain.handle('hermes:git:review:list', async (_event, repoPath, scope, baseRef) =>
+    reviewList(repoPath, scope, baseRef, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:diff', async (_event, repoPath, filePath, scope, baseRef, staged) =>
+    reviewDiff(repoPath, filePath, scope, baseRef, staged, resolveGitBinary())
+  )
+  // Working-tree-vs-HEAD diff for one file (the preview's "show the diff" view).
+  ipcMain.handle('hermes:git:fileDiff', async (_event, repoPath, filePath) =>
+    fileDiffVsHead(repoPath, filePath, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:stage', async (_event, repoPath, filePath) =>
+    reviewStage(repoPath, filePath ?? null, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:unstage', async (_event, repoPath, filePath) =>
+    reviewUnstage(repoPath, filePath ?? null, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:revert', async (_event, repoPath, filePath) =>
+    reviewRevert(repoPath, filePath ?? null, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:revParse', async (_event, repoPath, ref) =>
+    reviewRevParse(repoPath, ref, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:commit', async (_event, repoPath, message, push) =>
+    reviewCommit(repoPath, message, Boolean(push), resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:commitContext', async (_event, repoPath) =>
+    reviewCommitContext(repoPath, resolveGitBinary())
+  )
+  ipcMain.handle('hermes:git:review:push', async (_event, repoPath) => reviewPush(repoPath, resolveGitBinary()))
+  ipcMain.handle('hermes:git:review:shipInfo', async (_event, repoPath) => reviewShipInfo(repoPath, resolveGhBinary()))
+  ipcMain.handle('hermes:git:review:createPr', async (_event, repoPath) =>
+    reviewCreatePr(repoPath, resolveGitBinary(), resolveGhBinary())
+  )
+
+  // Repo-first project discovery: scan bounded roots for git repos (pure fs walk,
+  // no native addon). Never throws to the renderer — failures yield an empty list.
+  ipcMain.handle('hermes:git:scanRepos', async (_event, roots, options) => {
+    try {
+      return await scanGitRepos(roots || [], options || {})
+    } catch {
+      return []
+    }
+  })
+}
+
+module.exports = { registerGitIpc }

apps/desktop/electron/git-ipc.test.cjs

@@ -0,0 +1,61 @@
+'use strict'
+
+const assert = require('node:assert/strict')
+const test = require('node:test')
+
+const { registerGitIpc } = require('./git-ipc.cjs')
+
+function fakeIpcMain() {
+  const handlers = new Map()
+
+  return {
+    handlers,
+    handle(channel, handler) {
+      assert.ok(!handlers.has(channel), `duplicate registration for ${channel}`)
+      handlers.set(channel, handler)
+    }
+  }
+}
+
+test('registerGitIpc wires only hermes:git:* channels, each to a handler fn', () => {
+  const ipcMain = fakeIpcMain()
+
+  registerGitIpc({ ipcMain, resolveGitBinary: () => 'git', resolveGhBinary: () => 'gh' })
+
+  assert.ok(ipcMain.handlers.size >= 19, `expected the full git surface, got ${ipcMain.handlers.size}`)
+
+  for (const [channel, handler] of ipcMain.handlers) {
+    assert.match(channel, /^hermes:git:/, `${channel} is not a git channel`)
+    assert.equal(typeof handler, 'function', `${channel} should register a handler`)
+  }
+
+  // Spot-check the load-bearing channels across the worktree / review / scan groups.
+  for (const channel of ['hermes:git:worktreeList', 'hermes:git:review:commit', 'hermes:git:scanRepos']) {
+    assert.ok(ipcMain.handlers.has(channel), `missing ${channel}`)
+  }
+})
+
+test('handlers thread the injected resolver into the ops layer', async () => {
+  const ipcMain = fakeIpcMain()
+  const calls = []
+
+  registerGitIpc({
+    ipcMain,
+    resolveGitBinary: () => {
+      calls.push('git')
+
+      return 'git'
+    },
+    resolveGhBinary: () => 'gh'
+  })
+
+  // The resolver is consulted synchronously to build the ops call; whatever the
+  // ops layer does with a non-repo path is irrelevant to the wiring.
+  try {
+    await ipcMain.handlers.get('hermes:git:worktreeList')({}, '/definitely/not/a/repo')
+  } catch {
+    // ops layer may reject on a bad path — not what this test asserts.
+  }
+
+  assert.deepEqual(calls, ['git'])
+})

apps/desktop/electron/main.cjs

@@ -58,23 +58,7 @@ const {
   buildRelaunchScript
 } = require('./update-relaunch.cjs')
 const { gitRootForIpc } = require('./git-root.cjs')
-const { addWorktree, listBranches, listWorktrees, removeWorktree, switchBranch } = require('./git-worktree-ops.cjs')
-const {
-  fileDiffVsHead,
-  repoStatus,
-  reviewCommit,
-  reviewCommitContext,
-  reviewCreatePr,
-  reviewDiff,
-  reviewList,
-  reviewPush,
-  reviewRevParse,
-  reviewRevert,
-  reviewShipInfo,
-  reviewStage,
-  reviewUnstage
-} = require('./git-review-ops.cjs')
-const { scanGitRepos } = require('./git-repo-scan.cjs')
+const { registerGitIpc } = require('./git-ipc.cjs')
 const { OFFICIAL_REPO_HTTPS_URL, isOfficialSshRemote } = require('./update-remote.cjs')
 const { resolveBehindCount, shouldCountCommits } = require('./update-count.cjs')
 const { runRebuildWithRetry } = require('./update-rebuild.cjs')
@@ -1361,10 +1345,7 @@ function backendSupportsServe(backend) {
   let supported = null
   if (backend.root) {
     try {
-      const src = fs.readFileSync(
-        path.join(backend.root, 'hermes_cli', 'subcommands', 'dashboard.py'),
-        'utf8'
-      )
+      const src = fs.readFileSync(path.join(backend.root, 'hermes_cli', 'subcommands', 'dashboard.py'), 'utf8')
       supported = sourceDeclaresServe(src)
     } catch {
       supported = null // source unreadable — fall through to the probe
@@ -2292,9 +2273,7 @@ async function handOffWindowsBootstrapRecovery(reason) {
   // --repair (full venv recreate) and drove reinstall loops. The venv interpreter
   // and the bootstrap-complete marker are present earlier and are better signals.
   const haveRealInstall =
-    fileExists(venvPython) ||
-    fileExists(venvHermes) ||
-    fileExists(path.join(updateRoot, '.hermes-bootstrap-complete'))
+    fileExists(venvPython) || fileExists(venvHermes) || fileExists(path.join(updateRoot, '.hermes-bootstrap-complete'))
   const updaterArgs = haveRealInstall ? ['--update', '--branch', branch] : ['--repair', '--branch', branch]
 
   await releaseBackendLockForUpdate(updateRoot)
@@ -7008,75 +6987,9 @@ ipcMain.handle('hermes:fs:trash', async (_event, targetPath) => {
   return true
 })
 
-// Git-driven worktree management ("Start work" flow). Errors surface to the
-// renderer as rejected promises so it can toast a friendly message.
-ipcMain.handle('hermes:git:worktreeList', async (_event, repoPath) => listWorktrees(repoPath, resolveGitBinary()))
-
-ipcMain.handle('hermes:git:worktreeAdd', async (_event, repoPath, options) =>
-  addWorktree(repoPath, options || {}, resolveGitBinary())
-)
-
-ipcMain.handle('hermes:git:worktreeRemove', async (_event, repoPath, worktreePath, options) =>
-  removeWorktree(repoPath, worktreePath, options || {}, resolveGitBinary())
-)
-
-ipcMain.handle('hermes:git:branchSwitch', async (_event, repoPath, branch) =>
-  switchBranch(repoPath, branch, resolveGitBinary())
-)
-
-ipcMain.handle('hermes:git:branchList', async (_event, repoPath) => listBranches(repoPath, resolveGitBinary()))
-
-// Compact repo status (branch, ahead/behind, change counts + files) for the
-// composer coding rail. Returns null on a non-repo / remote backend so the rail
-// hides cleanly rather than erroring.
-ipcMain.handle('hermes:git:repoStatus', async (_event, repoPath) => repoStatus(repoPath, resolveGitBinary()))
-
-// Codex-style review pane: list changed files for a scope, fetch one file's
-// unified diff, and stage / unstage / revert. Reads return empty on failure;
-// mutations reject so the renderer can toast.
-ipcMain.handle('hermes:git:review:list', async (_event, repoPath, scope, baseRef) =>
-  reviewList(repoPath, scope, baseRef, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:diff', async (_event, repoPath, filePath, scope, baseRef, staged) =>
-  reviewDiff(repoPath, filePath, scope, baseRef, staged, resolveGitBinary())
-)
-// Working-tree-vs-HEAD diff for one file (the preview's "show the diff" view).
-ipcMain.handle('hermes:git:fileDiff', async (_event, repoPath, filePath) =>
-  fileDiffVsHead(repoPath, filePath, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:stage', async (_event, repoPath, filePath) =>
-  reviewStage(repoPath, filePath ?? null, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:unstage', async (_event, repoPath, filePath) =>
-  reviewUnstage(repoPath, filePath ?? null, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:revert', async (_event, repoPath, filePath) =>
-  reviewRevert(repoPath, filePath ?? null, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:revParse', async (_event, repoPath, ref) =>
-  reviewRevParse(repoPath, ref, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:commit', async (_event, repoPath, message, push) =>
-  reviewCommit(repoPath, message, Boolean(push), resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:commitContext', async (_event, repoPath) =>
-  reviewCommitContext(repoPath, resolveGitBinary())
-)
-ipcMain.handle('hermes:git:review:push', async (_event, repoPath) => reviewPush(repoPath, resolveGitBinary()))
-ipcMain.handle('hermes:git:review:shipInfo', async (_event, repoPath) => reviewShipInfo(repoPath, resolveGhBinary()))
-ipcMain.handle('hermes:git:review:createPr', async (_event, repoPath) =>
-  reviewCreatePr(repoPath, resolveGitBinary(), resolveGhBinary())
-)
-
-// Repo-first project discovery: scan bounded roots for git repos (pure fs walk,
-// no native addon). Never throws to the renderer — failures yield an empty list.
-ipcMain.handle('hermes:git:scanRepos', async (_event, roots, options) => {
-  try {
-    return await scanGitRepos(roots || [], options || {})
-  } catch {
-    return []
-  }
-})
+// Git/worktree/review IPC lives in git-ipc.cjs; the git + gh binary resolvers
+// stay here (Windows PATH discovery) and are injected into the registrar.
+registerGitIpc({ ipcMain, resolveGitBinary, resolveGhBinary })
 
 ipcMain.handle('hermes:terminal:start', async (event, payload = {}) => {
   if (!nodePty) {

apps/desktop/package.json

@@ -37,7 +37,7 @@
     "test:desktop:nsis": "node scripts/test-desktop.mjs nsis",
     "test:desktop:existing": "node scripts/test-desktop.mjs existing",
     "test:desktop:fresh": "node scripts/test-desktop.mjs fresh",
-    "test:desktop:platforms": "node --test electron/bootstrap-platform.test.cjs electron/hardening.test.cjs electron/backend-env.test.cjs electron/backend-probes.test.cjs electron/backend-ready.test.cjs electron/bootstrap-runner.test.cjs electron/connection-config.test.cjs electron/dashboard-token.test.cjs electron/gateway-ws-probe.test.cjs electron/oauth-net-request.test.cjs electron/desktop-uninstall.test.cjs electron/session-windows.test.cjs electron/link-title-window.test.cjs electron/workspace-cwd.test.cjs electron/fs-read-dir.test.cjs electron/git-root.test.cjs electron/git-worktree-ops.test.cjs electron/windows-child-process.test.cjs electron/update-remote.test.cjs electron/update-count.test.cjs electron/update-rebuild.test.cjs electron/update-marker.test.cjs electron/update-relaunch.test.cjs electron/windows-user-env.test.cjs electron/wsl-clipboard-image.test.cjs electron/titlebar-overlay-width.test.cjs electron/window-state.test.cjs electron/windows-hermes-resolution.test.cjs",
+    "test:desktop:platforms": "node --test electron/bootstrap-platform.test.cjs electron/hardening.test.cjs electron/backend-env.test.cjs electron/backend-probes.test.cjs electron/backend-ready.test.cjs electron/bootstrap-runner.test.cjs electron/connection-config.test.cjs electron/dashboard-token.test.cjs electron/gateway-ws-probe.test.cjs electron/oauth-net-request.test.cjs electron/desktop-uninstall.test.cjs electron/session-windows.test.cjs electron/link-title-window.test.cjs electron/workspace-cwd.test.cjs electron/fs-read-dir.test.cjs electron/git-root.test.cjs electron/git-ipc.test.cjs electron/git-worktree-ops.test.cjs electron/windows-child-process.test.cjs electron/update-remote.test.cjs electron/update-count.test.cjs electron/update-rebuild.test.cjs electron/update-marker.test.cjs electron/update-relaunch.test.cjs electron/windows-user-env.test.cjs electron/wsl-clipboard-image.test.cjs electron/titlebar-overlay-width.test.cjs electron/window-state.test.cjs electron/windows-hermes-resolution.test.cjs",
     "typecheck": "tsc -p . --noEmit",
     "lint": "eslint src/ electron/",
     "lint:fix": "eslint src/ electron/ --fix",