refactor(desktop): extract app-version IPC from main.cjs into version-ipc.cjs

Ninth main.cjs cluster peel. The hermes:version handler moves verbatim into
electron/version-ipc.cjs behind a registerVersionIpc({ ipcMain,
resolveHermesVersion, resolveUpdateRoot }) registrar. The version + root resolvers
stay in the main process (shared with the About menu) and are injected.

Channel name unchanged → preload + renderer untouched. Adds
electron/version-ipc.test.cjs (surface + payload behavior).

apps/desktop/electron/main.cjs

@@ -63,6 +63,7 @@ const { registerLogsIpc } = require('./logs-ipc.cjs')
 const { registerProjectDirIpc } = require('./project-dir-ipc.cjs')
 const { registerVscodeThemeIpc } = require('./vscode-theme-ipc.cjs')
 const { registerUninstallIpc } = require('./uninstall-ipc.cjs')
+const { registerVersionIpc } = require('./version-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')
@@ -6929,13 +6930,8 @@ function showAboutPanelFresh() {
   app.showAboutPanel()
 }
 
-ipcMain.handle('hermes:version', async () => ({
-  appVersion: resolveHermesVersion(),
-  electronVersion: process.versions.electron,
-  nodeVersion: process.versions.node,
-  platform: process.platform,
-  hermesRoot: resolveUpdateRoot()
-}))
+// App-version IPC lives in version-ipc.cjs; the version + root resolvers are injected.
+registerVersionIpc({ ipcMain, resolveHermesVersion, resolveUpdateRoot })
 
 // ===========================================================================
 // Uninstall — remove the Chat GUI (and optionally the agent / user data).

apps/desktop/electron/version-ipc.cjs

@@ -0,0 +1,17 @@
+'use strict'
+
+// App-version IPC: report the canonical Hermes version (resolved from the source
+// tree, falling back to the Electron app version) alongside the Electron/Node
+// runtime versions + the resolved Hermes root. The version + root resolvers live
+// in the main process and are injected.
+function registerVersionIpc({ ipcMain, resolveHermesVersion, resolveUpdateRoot }) {
+  ipcMain.handle('hermes:version', async () => ({
+    appVersion: resolveHermesVersion(),
+    electronVersion: process.versions.electron,
+    nodeVersion: process.versions.node,
+    platform: process.platform,
+    hermesRoot: resolveUpdateRoot()
+  }))
+}
+
+module.exports = { registerVersionIpc }

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

@@ -0,0 +1,41 @@
+'use strict'
+
+const assert = require('node:assert/strict')
+const test = require('node:test')
+
+const { registerVersionIpc } = require('./version-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('registerVersionIpc wires hermes:version to a handler fn', () => {
+  const ipcMain = fakeIpcMain()
+
+  registerVersionIpc({ ipcMain, resolveHermesVersion: () => '1.2.3', resolveUpdateRoot: () => '/root' })
+
+  assert.deepEqual([...ipcMain.handlers.keys()], ['hermes:version'])
+  assert.equal(typeof ipcMain.handlers.get('hermes:version'), 'function')
+})
+
+test('version reports the resolved Hermes version + root alongside runtime versions', async () => {
+  const ipcMain = fakeIpcMain()
+
+  registerVersionIpc({ ipcMain, resolveHermesVersion: () => '1.2.3', resolveUpdateRoot: () => '/root' })
+
+  const res = await ipcMain.handlers.get('hermes:version')({})
+
+  assert.equal(res.appVersion, '1.2.3')
+  assert.equal(res.hermesRoot, '/root')
+  assert.equal(res.electronVersion, process.versions.electron)
+  assert.equal(res.nodeVersion, process.versions.node)
+  assert.equal(res.platform, process.platform)
+})