feat: add config profiles

- Add ConfigProfile and ConfigProfileInclude data models with migrations
- Implement profile resolver service with ordered includes and merge rules
- Add profile CRUD API with validation, compatibility, and cycle detection
- Add instance API plumbing for profile selection on create/start/restart
- Add resolved profile preview and default resolution APIs
- Add frontend config profile API client and management UI
- Add launch/restart profile selection UI
- Add backend integration and unit tests (31 passing)

OpenSpec: add-config-profiles
Quality gates: ruff, TypeScript compile, 31 tests passing

apps/api/src/main.py

@@ -18,6 +18,7 @@ from src.api.ssh_keys import router as ssh_keys_router
 from src.api.terminal import router as terminal_router
 from src.api.instance_proxy import router as instance_proxy_router
 from src.api.config_folders import router as config_folders_router
+from src.api.config_profiles import router as config_profiles_router
 from src.api.tool_configs import router as tool_configs_router
 from src.api.tool_instances import router as tool_instances_router
 from src.api.tool_instances import sessions_router
@@ -125,6 +126,7 @@ app.include_router(git_repositories_router)
 app.include_router(user_config_router)
 app.include_router(tool_types_router)
 app.include_router(config_folders_router)
+app.include_router(config_profiles_router)
 app.include_router(tool_instances_router)
 app.include_router(tool_configs_router)
 app.include_router(sessions_router)