Fix Docker test infrastructure

Fixed multiple issues in docker/test-env:
- Changed Node.js installation to use official NodeSource repo (fixes npm compatibility)
- Made repository volume mounts writable (removed :ro flag)
- Fixed agents copy path (removed incorrect /agents/ subdirectory)
- Fixed critical agent paths (studio-coach in bonus/, removed agent-updater)
- Added explicit log file creation to fix permission errors
- Removed test-results volume mount (caused permission issues)

Test results: Manual installation now shows 28/35 tests passing
- All 38 agents install correctly
- All critical agents verified
- MCP tools accessible via npx
- Minor: Claude Code verification script has false negative
- Minor: MCP global npm installs fail (network issue, npx works)

docker/test-env/docker-compose.yml

@@ -8,7 +8,7 @@ services:
       dockerfile: Dockerfile
     container_name: claude-interactive-test
     volumes:
-      - ../../:/home/testman/claude-code-glm-suite:ro
+      - ../../:/home/testman/claude-code-glm-suite
     environment:
       - TEST_MODE=interactive
       - ANTHROPIC_AUTH_TOKEN=${ANTHROPIC_AUTH_TOKEN:-test-token}
@@ -23,7 +23,7 @@ services:
       dockerfile: Dockerfile
     container_name: claude-master-prompt-test
     volumes:
-      - ../../:/home/testuser/claude-code-glm-suite:ro
+      - ../../:/home/testuser/claude-code-glm-suite
     environment:
       - TEST_MODE=master-prompt
       - ANTHROPIC_AUTH_TOKEN=${ANTHROPIC_AUTH_TOKEN:-test-token}
@@ -38,7 +38,7 @@ services:
       dockerfile: Dockerfile
     container_name: claude-manual-test
     volumes:
-      - ../../:/home/testuser/claude-code-glm-suite:ro
+      - ../../:/home/testuser/claude-code-glm-suite
     environment:
       - TEST_MODE=manual
       - ANTHROPIC_AUTH_TOKEN=${ANTHROPIC_AUTH_TOKEN:-test-token}
@@ -53,8 +53,7 @@ services:
       dockerfile: Dockerfile
     container_name: claude-verify-all
     volumes:
-      - ../../:/home/testuser/claude-code-glm-suite:ro
-      - ./test-results:/home/testuser/test-results
+      - ../../:/home/testuser/claude-code-glm-suite
     environment:
       - TEST_MODE=verify
     command: /home/testuser/test-suite/verify-all-installations.sh