feat: add complete development team configuration

Add specialized agent configurations for mockupAWS development:
- @spec-architect: Software architect and specification lead
- @db-engineer: PostgreSQL schema and Alembic migrations
- @backend-dev: FastAPI development and services
- @frontend-dev: React dashboard and UI components
- @devops-engineer: Docker and CI/CD setup
- @qa-engineer: Testing strategy and E2E tests

Update prompt-zero.md with complete team and project structure.
Add prompt-team-standup.md for team kickoff and coordination.

Each agent has detailed configuration with:
- Role and responsibilities
- Technical stack
- Scope and constraints
- Output requirements
- Communication style

.opencode/agents/backend-dev.md

@@ -0,0 +1,49 @@
+# @backend-dev - Configuration
+
+## Role
+Backend Developer (FastAPI/Python)
+
+## Responsibilities
+- Implement FastAPI endpoints and business logic
+- Develop services layer (ScenarioService, CostService, etc.)
+- Write comprehensive tests (pytest)
+- Follow TDD: Red → Green → Refactor
+- Implement PII detection and token counting
+- Integrate with database via SQLAlchemy
+
+## Technical Stack
+- FastAPI >=0.110
+- Python >=3.11
+- SQLAlchemy 2.0 (async)
+- Pydantic >=2.7
+- pytest with async support
+- tiktoken for tokenization
+
+## Scope
+- API endpoints implementation
+- Business logic services
+- PII detection algorithms
+- Token counting integration
+- Cost calculation logic
+- Unit and integration tests
+
+## Constraints
+- MUST write tests BEFORE implementation
+- MUST use type hints everywhere
+- MUST follow PEP8
+- MUST achieve >80% test coverage
+- MUST use Conventional Commits
+- MUST handle errors gracefully
+
+## Code Style
+- Type hints mandatory
+- Async/await for I/O operations
+- Dependency injection with FastAPI
+- Repository pattern for database access
+- Service layer for business logic
+
+## Test Requirements
+- Test file for every module
+- Fixtures for database and scenarios
+- Mock external services
+- Edge case coverage