feat: Add explorer and synthesizer roles with commands for codebase exploration and synthesis

- Implemented `explorer` role for parallel codebase exploration using `cli-explore-agent`.
- Created `explore.md` command documentation detailing exploration strategy and execution steps.
- Established `synthesizer` role for integrating insights from explorations, analyses, and discussions.
- Developed `synthesize.md` command documentation outlining synthesis strategy and output format.
- Configured team settings in `team-config.json` to support new roles and pipeline modes.
- Added regression test for CodexLens bootstrap fallback to ensure robustness in error handling.

ccw/tests/codex-lens-bootstrap-fallback.test.js

@@ -0,0 +1,93 @@
+/**
+ * Regression test: CodexLens bootstrap falls back to pip when UV bootstrap fails.
+ *
+ * We simulate a "broken UV" by pointing CCW_UV_PATH to the current Node executable.
+ * `node --version` exits 0 so isUvAvailable() returns true, but `node venv ...` fails,
+ * forcing the bootstrap code to try the pip path.
+ *
+ * This test runs bootstrapVenv in a child process to avoid mutating process-wide
+ * environment variables that could affect other tests.
+ */
+
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { spawn } from 'node:child_process';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { tmpdir } from 'node:os';
+import { fileURLToPath } from 'node:url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+// repo root: <repo>/ccw/tests -> <repo>
+const REPO_ROOT = join(__dirname, '..', '..');
+
+function runNodeEvalModule(script, env) {
+  return new Promise((resolve, reject) => {
+    const child = spawn(process.execPath, ['--input-type=module', '-e', script], {
+      cwd: REPO_ROOT,
+      env,
+      stdio: ['ignore', 'pipe', 'pipe'],
+      windowsHide: true,
+    });
+
+    let stdout = '';
+    let stderr = '';
+
+    child.stdout.on('data', (d) => { stdout += d.toString(); });
+    child.stderr.on('data', (d) => { stderr += d.toString(); });
+
+    child.on('error', (err) => reject(err));
+    child.on('close', (code) => resolve({ code, stdout, stderr }));
+  });
+}
+
+describe('CodexLens bootstrap fallback', () => {
+  it('falls back to pip when UV bootstrap fails', { timeout: 10 * 60 * 1000 }, async () => {
+    const dataDir = mkdtempSync(join(tmpdir(), 'codexlens-bootstrap-fallback-'));
+
+    try {
+      const script = `
+import { bootstrapVenv } from './ccw/dist/tools/codex-lens.js';
+
+(async () => {
+  const result = await bootstrapVenv();
+  console.log('@@RESULT@@' + JSON.stringify(result));
+})().catch((e) => {
+  console.error(e?.stack || String(e));
+  process.exit(1);
+});
+`;
+
+      const env = {
+        ...process.env,
+        // Isolate test venv + dependencies from user/global CodexLens state.
+        CODEXLENS_DATA_DIR: dataDir,
+        // Make isUvAvailable() return true, but createVenv() fail.
+        CCW_UV_PATH: process.execPath,
+      };
+
+      const { code, stdout, stderr } = await runNodeEvalModule(script, env);
+      assert.equal(code, 0, `bootstrapVenv child process failed:\nSTDOUT:\n${stdout}\nSTDERR:\n${stderr}`);
+
+      const marker = '@@RESULT@@';
+      const idx = stdout.lastIndexOf(marker);
+      assert.ok(idx !== -1, `Missing result marker in stdout:\n${stdout}`);
+
+      const jsonText = stdout.slice(idx + marker.length).trim();
+      const parsed = JSON.parse(jsonText);
+
+      assert.equal(parsed?.success, true, `Expected success=true, got:\n${jsonText}`);
+      assert.ok(Array.isArray(parsed.warnings), 'Expected warnings array on pip fallback result');
+      assert.ok(parsed.warnings.some((w) => String(w).includes('UV bootstrap failed')), `Expected UV failure warning, got: ${JSON.stringify(parsed.warnings)}`);
+    } finally {
+      try {
+        rmSync(dataDir, { recursive: true, force: true });
+      } catch {
+        // Best effort cleanup; leave artifacts only if Windows locks prevent removal.
+      }
+    }
+  });
+});
+