C7: keep the required-mode hook's exit-2 deny

Copilot CLI treats a preToolUse exit 2 as deny (its hooks reference), and
#2413 established exit 2 plus hookSpecificOutput as the shape Claude Code
enforces, so the deny output stays as on main; only the matcher and the
in-place upgrade of older 'Skill' entries change.

bin/gstack-team-init

@@ -151,10 +151,10 @@ Install it:
 
 Then restart your AI coding tool.
 MSG
-  # Claude Code reads hookSpecificOutput; Copilot CLI reads the top-level
-  # fields (#2229). Exit 0 so both parse the decision instead of an error.
-  echo '{"permissionDecision":"deny","permissionDecisionReason":"gstack is required but not installed. See stderr for install instructions.","hookSpecificOutput":{"hookEventName":"PreToolUse","permissionDecision":"deny","permissionDecisionReason":"gstack is required but not installed. See stderr for install instructions."}}'
-  exit 0
+  # Exit 2 denies on Claude Code (#2413) and on Copilot CLI, which treats a
+  # preToolUse exit 2 as deny (#2229).
+  echo '{"hookSpecificOutput":{"hookEventName":"PreToolUse","permissionDecision":"deny","permissionDecisionReason":"gstack is required but not installed. See stderr for install instructions."}}'
+  exit 2
 fi
 
 echo '{}'

test/team-mode.test.ts

@@ -2,7 +2,7 @@ import { describe, test, expect, beforeEach, afterEach } from 'bun:test';
 import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
-import { execSync, spawnSync } from 'child_process';
+import { execSync } from 'child_process';
 import { createHash } from 'crypto';
 import { runBashScript } from './helpers/bash-script';
 
@@ -267,24 +267,6 @@ describe('gstack-team-init', () => {
     expect(pre.map((e: { matcher: string }) => e.matcher)).toEqual(['Bash', 'Skill|skill']);
   });
 
-  test('required: the hook denies in both Claude Code and Copilot CLI decision formats (C7)', () => {
-    run(`${TEAM_INIT} required`, { cwd: tmpDir });
-    const home = mkTmpDir();
-    try {
-      const r = spawnSync('bash', [path.join(tmpDir, '.claude', 'hooks', 'check-gstack.sh')], {
-        encoding: 'utf-8', timeout: 30_000, env: { PATH: process.env.PATH ?? '/usr/bin:/bin', HOME: home },
-      });
-      expect(r.status).toBe(0);
-      const out = JSON.parse(r.stdout);
-      expect(out.permissionDecision).toBe('deny');
-      expect(out.permissionDecisionReason).toContain('gstack is required');
-      expect(out.hookSpecificOutput).toMatchObject({ hookEventName: 'PreToolUse', permissionDecision: 'deny' });
-      expect(r.stderr).toContain('BLOCKED: gstack is not installed');
-    } finally {
-      fs.rmSync(home, { recursive: true, force: true });
-    }
-  });
-
   test('idempotent: running twice does not duplicate CLAUDE.md section', () => {
     run(`${TEAM_INIT} optional`, { cwd: tmpDir });
     run(`${TEAM_INIT} optional`, { cwd: tmpDir });