fix(pi): cap the project picker at 20 rows so it does not fill the screen

pi's ExtensionSelectorComponent.updateList() renders every option with no
windowing, so 50 rows scrolled the transcript away. prime-agent's selector
windows to ~20 itself and shows a true (20/356) counter; matching that height
makes both hosts behave the same.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017BMXdb2qZbPSh8Q7XpTyjB

src/cli/tests/commands/prime-agent.test.ts

@@ -528,6 +528,38 @@ describe('config prime-agent', () => {
     expect(ext).not.toContain("'success'");
   });
 
+  it('the installed switcher shows the active project via a widget, not just setStatus', async () => {
+    const settingsPath = join(tmpDir, 'settings.json');
+    const cmd = createConfigCommand(
+      { configDeps: { configDir: tmpDir }, log },
+      { client, credentialsDeps: { configDir: tmpDir }, log },
+    );
+    await cmd.parseAsync(['prime-agent', '--project', 'ha', '-o', settingsPath, '--skip-skills', '--token', 'mcpctl_pat_x'], { from: 'user' });
+
+    const ext = readFileSync(join(tmpDir, 'extensions', 'mcpctl-switch.ts'), 'utf-8');
+    // prime-agent stores extension statuses but never renders them, so a
+    // setStatus-only indicator is invisible there. Widgets are rendered.
+    expect(ext).toContain('ctx.ui.setWidget(STATUS_KEY');
+    expect(ext).toContain("placement: 'belowEditor'");
+    // Still set the status: pi's footer does render it.
+    expect(ext).toContain('ctx.ui.setStatus(STATUS_KEY');
+  });
+
+  it('the installed switcher filters the project list before showing it', async () => {
+    const settingsPath = join(tmpDir, 'settings.json');
+    const cmd = createConfigCommand(
+      { configDeps: { configDir: tmpDir }, log },
+      { client, credentialsDeps: { configDir: tmpDir }, log },
+    );
+    await cmd.parseAsync(['prime-agent', '--project', 'ha', '-o', settingsPath, '--skip-skills', '--token', 'mcpctl_pat_x'], { from: 'user' });
+
+    const ext = readFileSync(join(tmpDir, 'extensions', 'mcpctl-switch.ts'), 'utf-8');
+    // Hundreds of projects in a plain arrow-key list is unusable.
+    expect(ext).toContain('export function filterProjects');
+    expect(ext).toContain('ctx.ui.input(');
+    expect(ext).toContain('FILTER_THRESHOLD');
+  });
+
   it('the installed switcher extension passes --skip-marker', async () => {
     const settingsPath = join(tmpDir, 'settings.json');
     const cmd = createConfigCommand(

src/pi-ext/mcpctl-pi.ts

@@ -450,8 +450,13 @@ export default function (pi: ExtensionAPI) {
 
   /** Above this many projects, arrowing through the list stops being usable. */
   const FILTER_THRESHOLD = 20;
-  /** Never render more than this in one selector, even after filtering. */
-  const MAX_SHOWN = 50;
+  /**
+   * Hard cap on rendered rows. pi's ExtensionSelectorComponent.updateList()
+   * renders *every* option with no windowing, so an uncapped list scrolls the
+   * whole screen away. prime-agent's selector windows to ~20 itself; this
+   * matches that height so both hosts feel the same.
+   */
+  const MAX_SHOWN = 20;
 
   /**
    * Choose a project, asking for a filter first when the list is long.