docs: add rel-003, rel-004 releases and update CLI user scoping implementation

Release: REL-003_20260512 — CLI user scoping and local DB ops runbook

Requirements & Batches:
- BAT-003 (REQ-013): portfolio list --user required enforcement with owner filtering
- BAT-004 (REQ-014): portfolio create --user required enforcement with owner assignment
- BAT-007 (REQ-001/002/003): local DB validation runbook and baseline docs update

CLI Enhancements:
- Update user.py: add username-based user lookup (get_by_username)
- Add UserDetailResponse schema with service token listing
- Update list_service_tokens API in user_service.py
- Enhance user detail display with service token information
- Add service_token_count and service_token_names to user responses

Testing:
- Add comprehensive test coverage in test_cli.py for user commands
- Validate username-based lookup functionality

Release: REL-004_20260512 — Portfolio UUID migration and API UUID switch

Requirements & Batches:
- BAT-006 (REQ-016/017/018): portfolio UUID migration complete
- BAT-008 (REQ-019): baseline documentation update for UUID migration

Breaking Changes (REL-003):
- portfolio list requires --user <username> parameter
- portfolio create requires --user <username> parameter

Documentation:
- Create rel-003 and rel-004 release documents with rollout and rollback plans
- Update docs/releases/index.md with new releases
- Update README.md with CLI user scoping clarification
- Sync all release verification checklists and deployment notes

app/schemas/user.py

@@ -19,6 +19,11 @@ class UserResponse(BaseModel):
     last_login_at: datetime | None = None
 
 
+class UserDetailResponse(UserResponse):
+    service_token_count: int = 0
+    service_token_names: list[str] = Field(default_factory=list)
+
+
 class CreateUserRequest(BaseModel):
     username: str = Field(min_length=1)
     email: str | None = None