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

Eighth main.cjs cluster peel. The two hermes:uninstall:* handlers (summary, run)
move verbatim into electron/uninstall-ipc.cjs behind a registerUninstallIpc({
ipcMain, getUninstallSummary, runDesktopUninstall }) registrar. The uninstall
engine stays in the main process and is injected.

Channel names unchanged → preload + renderer untouched. Adds
electron/uninstall-ipc.test.cjs (surface invariant + run mode normalization).

apps/desktop/electron/main.cjs

@@ -62,6 +62,7 @@ const { registerUpdatesIpc } = require('./updates-ipc.cjs')
 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 { OFFICIAL_REPO_HTTPS_URL, isOfficialSshRemote } = require('./update-remote.cjs')
 const { resolveBehindCount, shouldCountCommits } = require('./update-count.cjs')
 const { runRebuildWithRetry } = require('./update-rebuild.cjs')
@@ -7127,11 +7128,8 @@ async function runDesktopUninstall(mode) {
   return { ok: true, mode, willRemoveAppBundle: Boolean(removeBundle), scriptPath }
 }
 
-ipcMain.handle('hermes:uninstall:summary', async () => getUninstallSummary())
-ipcMain.handle('hermes:uninstall:run', async (_event, payload) => {
-  const mode = payload && typeof payload === 'object' ? payload.mode : payload
-  return runDesktopUninstall(String(mode || ''))
-})
+// Uninstall IPC lives in uninstall-ipc.cjs; the uninstall engine is injected.
+registerUninstallIpc({ getUninstallSummary, ipcMain, runDesktopUninstall })
 
 // VS Code Marketplace theme IPC lives in vscode-theme-ipc.cjs.
 registerVscodeThemeIpc({ ipcMain })

apps/desktop/electron/uninstall-ipc.cjs

@@ -0,0 +1,14 @@
+'use strict'
+
+// Uninstall IPC: summarize what a desktop uninstall would remove + run it
+// (GUI-only / lite / full). Both delegate to the main-process uninstall engine,
+// which is injected.
+function registerUninstallIpc({ getUninstallSummary, ipcMain, runDesktopUninstall }) {
+  ipcMain.handle('hermes:uninstall:summary', async () => getUninstallSummary())
+  ipcMain.handle('hermes:uninstall:run', async (_event, payload) => {
+    const mode = payload && typeof payload === 'object' ? payload.mode : payload
+    return runDesktopUninstall(String(mode || ''))
+  })
+}
+
+module.exports = { registerUninstallIpc }

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

@@ -0,0 +1,51 @@
+'use strict'
+
+const assert = require('node:assert/strict')
+const test = require('node:test')
+
+const { registerUninstallIpc } = require('./uninstall-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('registerUninstallIpc wires only hermes:uninstall:* channels, each to a handler fn', () => {
+  const ipcMain = fakeIpcMain()
+
+  registerUninstallIpc({ ipcMain, getUninstallSummary: async () => ({}), runDesktopUninstall: async () => ({}) })
+
+  assert.deepEqual([...ipcMain.handlers.keys()].sort(), ['hermes:uninstall:run', 'hermes:uninstall:summary'])
+
+  for (const handler of ipcMain.handlers.values()) {
+    assert.equal(typeof handler, 'function')
+  }
+})
+
+test('run normalizes both the {mode} object form and the bare-string form', async () => {
+  const ipcMain = fakeIpcMain()
+  const modes = []
+
+  registerUninstallIpc({
+    ipcMain,
+    getUninstallSummary: async () => ({}),
+    runDesktopUninstall: async mode => {
+      modes.push(mode)
+
+      return { mode }
+    }
+  })
+
+  await ipcMain.handlers.get('hermes:uninstall:run')({}, { mode: 'full' })
+  await ipcMain.handlers.get('hermes:uninstall:run')({}, 'lite')
+  await ipcMain.handlers.get('hermes:uninstall:run')({}, null)
+
+  assert.deepEqual(modes, ['full', 'lite', ''])
+})