chore: add skill directories

Author: gracefullight

.agents/skills/backend-agent/SKILL.md

@@ -0,0 +1,113 @@
+---
+name: backend-agent
+description: Backend specialist for APIs, databases, authentication using FastAPI with clean architecture (Repository/Service/Router pattern). Use for API, endpoint, REST, database, server, migration, and auth work.
+---
+
+# Backend Agent - API & Server Specialist
+
+## When to use
+- Building REST APIs or GraphQL endpoints
+- Database design and migrations
+- Authentication and authorization
+- Server-side business logic
+- Background jobs and queues
+
+## When NOT to use
+- Frontend UI -> use Frontend Agent
+- Mobile-specific code -> use Mobile Agent
+
+## Core Rules
+
+1. **DRY (Don't Repeat Yourself)**: Business logic in `Service`, data access logic in `Repository`
+2. **SOLID**:
+   - **Single Responsibility**: Classes and functions should have one responsibility
+   - **Dependency Inversion**: Use FastAPI's `Depends` for dependency injection
+3. **KISS**: Keep it simple and clear
+
+## Architecture Pattern
+
+```
+Router (HTTP) → Service (Business Logic) → Repository (Data Access) → Models
+```
+
+### Repository Layer
+- **File**: `src/[domain]/repository.py`
+- **Role**: Encapsulate DB CRUD and query logic
+- **Principle**: No business logic, return SQLAlchemy models
+
+### Service Layer
+- **File**: `src/[domain]/service.py`
+- **Role**: Business logic, Repository composition, external API calls
+- **Principle**: Business decisions only here
+
+### Router Layer
+- **File**: `src/[domain]/router.py`
+- **Role**: Receive HTTP requests, input validation, call Service, return response
+- **Principle**: No business logic, inject Service via DI
+
+## Core Rules
+
+1. **Clean architecture**: router → service → repository → models
+2. **No business logic in route handlers**
+3. **All inputs validated with Pydantic**
+4. **Parameterized queries only** (never string interpolation)
+5. **JWT + bcrypt for auth**; rate limit auth endpoints
+6. **Async/await consistently**; type hints on all signatures
+7. **Custom exceptions** via `src/lib/exceptions.py` (not raw HTTPException)
+8. **Explicit ORM loading strategy**: do not rely on default relation loading when query shape matters
+9. **Explicit transaction boundaries**: group one business operation into one request/service-scoped unit of work
+10. **Safe ORM lifecycle**: do not share mutable ORM session/entity manager/client objects across concurrent work unless the ORM explicitly supports it
+
+## Dependency Injection
+
+```python
+# src/recipes/routers/dependencies.py
+async def get_recipe_service(db: AsyncSession = Depends(get_db)) -> RecipeService:
+    repository = RecipeRepository(db)
+    return RecipeService(repository)
+
+# src/recipes/routers/base_router.py
+@router.get("/{recipe_id}")
+async def get_recipe(
+    recipe_id: str,
+    service: RecipeService = Depends(get_recipe_service)
+):
+    return await service.get_recipe(recipe_id)
+```
+
+## Code Quality
+
+- **Python 3.12+**: Strict type hints (mypy)
+- **Async/Await**: Required for I/O-bound operations
+- **Ruff**: Linting/formatting (Double Quotes, Line Length 100)
+
+## How to Execute
+
+Follow `resources/execution-protocol.md` step by step.
+See `resources/examples.md` for input/output examples.
+Use `resources/orm-reference.md` when the task involves ORM query performance, relationship loading, transactions, session/client lifecycle, or N+1 analysis.
+Before submitting, run `resources/checklist.md`.
+
+## Execution Protocol (CLI Mode)
+
+See `../_shared/execution-protocols/` for vendor-specific protocols.
+When spawned via `oh-my-ag agent:spawn`, the protocol is injected automatically.
+
+## References
+
+- Execution steps: `resources/execution-protocol.md`
+- Code examples: `resources/examples.md`
+- Code snippets: `resources/snippets.md`
+- Checklist: `resources/checklist.md`
+- ORM reference: `resources/orm-reference.md`
+- Error recovery: `resources/error-playbook.md`
+- Tech stack: `resources/tech-stack.md`
+- API template: `resources/api-template.py`
+- Context loading: `../_shared/context-loading.md`
+- Reasoning templates: `../_shared/reasoning-templates.md`
+- Clarification: `../_shared/clarification-protocol.md`
+- Context budget: `../_shared/context-budget.md`
+- Lessons learned: `../_shared/lessons-learned.md`
+
+> [!IMPORTANT]
+> When adding new modules, always include `__init__.py` to maintain package structure