fix(desktop): run the macOS Host from the helper so it takes no Dock tile (#149)

## Related Issue

No issue — reported directly: a second, unnamed icon appears in the
macOS Dock whenever the desktop app is running.

## Problem

The packaged app starts its Host by re-executing its own binary
(`Pythinker.app/Contents/MacOS/Pythinker`). macOS registers that child
with
LaunchServices as a second **foreground** application under the same
bundle id, so it takes a
Dock tile of its own. A bare executable has no icon, so the tile renders
with the generic
Unix-executable artwork next to the real app icon.

`ELECTRON_RUN_AS_NODE=1` is already set and is not the missing piece: it
stops the child from
becoming a browser process, but it does not affect LaunchServices
registration.

Observed on the installed 0.1.5 build:

```
90) "pythinker-code"  bundleID="com.pythinker.desktop"
    executable path="/Applications/Pythinker.app/Contents/MacOS/Pythinker"
    pid = 83782   type="Foreground"
    parentASN="Pythinker" (inferred)
```

## What changed

`resolveHostExecutable` picks the bundled Electron helper
(`Contents/Frameworks/<name> Helper.app`) as the Host runtime on macOS.
The helper declares
`LSUIElement`, so it registers as a UI element rather than a foreground
app and takes no Dock
tile, while running the identical Node runtime. It falls back to
`process.execPath` when the
bundle ships no matching helper, and non-macOS platforms are returned
unchanged.

Verified against the installed bundle:

```
same script via the app binary → type="Foreground"   (Dock tile)
same script via the helper     → type="UIElement"    (no Dock tile)
helper as a Node runtime       → node v24.18.1, electron 43.4.0
```

## Checklist

- [x] I have read the
[CONTRIBUTING](https://github.com/PyModel/pythinker-code/blob/main/CONTRIBUTING.md)
document.
- [ ] I have linked a related issue (external PRs: the issue must have a
maintainer's `/approve`).
- [x] I have added tests that prove my feature works. — 3 cases in
`apps/desktop/tests/host-supervisor.spec.ts`; reverting the fix turns
the first one red.
- [x] Ran `gen-changesets` skill, or this PR needs no changeset.
- [x] Ran `gen-docs` skill, or this PR needs no doc update.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Bug Fixes**
- Fixed a macOS Dock issue that could display a second unnamed Pythinker
icon while the app was running.
- Improved packaged desktop startup behavior across macOS, Windows, and
Linux.

- **Changes**
- Removed managed Kimi update checks, marketplace defaults, official
plugin badges, tips, and sign-up links.
- Kimi remains available as a model provider through OAuth or an API
key; marketplace access requires a configured marketplace URL.
  - Updated activity card wording to “subagent.”

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: elkaix

.changeset/desktop-dock-tile.md

@@ -0,0 +1,5 @@
+---
+"@pymodel/pythinker-desktop": patch
+---
+
+Stop a second, unnamed Pythinker icon appearing in the macOS Dock while the app runs.

apps/desktop/src/host-supervisor.ts

@@ -1,6 +1,7 @@
 /** Supervise the loopback Web Host used by the first desktop application. */
 
 import { spawn, spawnSync, type ChildProcessByStdio } from 'node:child_process'
+import { basename, join } from 'node:path'
 import type { Readable } from 'node:stream'
 
 const READINESS_PREFIX = 'Pythinker server: '
@@ -312,6 +313,31 @@ export function createHostSupervisor(options: HostSupervisorOptions): HostSuperv
   return { start, shutdown }
 }
 
+/**
+ * Resolve the executable that runs the Host on a packaged macOS app.
+ *
+ * The app must not re-exec its own main binary. LaunchServices registers that
+ * child as a second `Foreground` application under the same bundle id, so it
+ * takes a Dock tile of its own — drawn with the generic Unix-executable icon,
+ * since a bare executable has no icon to show. `ELECTRON_RUN_AS_NODE` stops the
+ * child from becoming a browser process but does not stop that registration.
+ * The bundled Electron helper declares `LSUIElement`, so it runs the very same
+ * Node runtime with no Dock tile and no second app.
+ * @param options - Platform, the app's own executable, its `Frameworks` directory, and an existence probe.
+ * @returns The helper executable when the bundle ships one, otherwise `execPath` unchanged.
+ */
+export function resolveHostExecutable(options: {
+  readonly platform: string
+  readonly execPath: string
+  readonly frameworksPath: string
+  readonly exists: (path: string) => boolean
+}): string {
+  if (options.platform !== 'darwin') return options.execPath
+  const name = basename(options.execPath)
+  const helper = join(options.frameworksPath, `${name} Helper.app`, 'Contents', 'MacOS', `${name} Helper`)
+  return options.exists(helper) ? helper : options.execPath
+}
+
 /** Options for the real Pythinker server child. */
 export interface SpawnPythinkerServerOptions {
   /** Node-compatible executable selected by the desktop app. */

apps/desktop/src/main.ts

@@ -30,6 +30,7 @@ import {
   isPortInUseError,
   parseRunningServerConflict,
   resolveDesktopPort,
+  resolveHostExecutable,
   spawnPythinkerServer,
   type HostSupervisor,
 } from './host-supervisor'
@@ -112,7 +113,12 @@ function hostPaths(): { nodeExecutable: string; cliEntry: string; cwd: string; e
     }
   }
   return {
-    nodeExecutable: process.execPath,
+    nodeExecutable: resolveHostExecutable({
+      platform: process.platform,
+      execPath: process.execPath,
+      frameworksPath: join(process.resourcesPath, '..', 'Frameworks'),
+      exists: existsSync,
+    }),
     cliEntry: join(process.resourcesPath, 'host/node_modules/@pymodel/pythinker-code/dist/main.mjs'),
     cwd: app.getPath('home'),
     electronRunAsNode: true,

apps/desktop/tests/host-supervisor.spec.ts

@@ -3,6 +3,7 @@ import { afterEach, describe, expect, it, vi } from 'vitest'
 import {
   createHostSupervisor,
   createReadinessParser,
+  resolveHostExecutable,
   type HostChild,
 } from '../src/host-supervisor'
 import * as hostSupervisor from '../src/host-supervisor'
@@ -509,3 +510,51 @@ describe('desktop Host process', () => {
     expect(spawnSync).not.toHaveBeenCalled()
   })
 })
+
+describe('resolveHostExecutable', () => {
+  const APP = '/Applications/Pythinker.app/Contents/MacOS/Pythinker'
+  const FRAMEWORKS = '/Applications/Pythinker.app/Contents/Frameworks'
+  const HELPER = `${FRAMEWORKS}/Pythinker Helper.app/Contents/MacOS/Pythinker Helper`
+
+  it('runs the Host from the LSUIElement helper so it takes no Dock tile of its own', () => {
+    // Re-execing the app's own binary registers a second Foreground app under
+    // the same bundle id, which shows up as a stray generic-executable icon in
+    // the Dock next to the real app.
+    const seen: string[] = []
+    const resolved = resolveHostExecutable({
+      platform: 'darwin',
+      execPath: APP,
+      frameworksPath: FRAMEWORKS,
+      exists: path => {
+        seen.push(path)
+        return path === HELPER
+      },
+    })
+    expect(resolved).toBe(HELPER)
+    expect(seen).toEqual([HELPER])
+  })
+
+  it('keeps the app executable when the bundle ships no matching helper', () => {
+    expect(
+      resolveHostExecutable({
+        platform: 'darwin',
+        execPath: APP,
+        frameworksPath: FRAMEWORKS,
+        exists: () => false,
+      }),
+    ).toBe(APP)
+  })
+
+  it('leaves non-macOS platforms alone', () => {
+    for (const platform of ['win32', 'linux']) {
+      expect(
+        resolveHostExecutable({
+          platform,
+          execPath: 'C:\\Program Files\\Pythinker\\Pythinker.exe',
+          frameworksPath: 'C:\\Program Files\\Pythinker\\Frameworks',
+          exists: () => true,
+        }),
+      ).toBe('C:\\Program Files\\Pythinker\\Pythinker.exe')
+    }
+  })
+})