fix: clear all addressable technical debt (DEBT-005 through DEBT-025)

Security:
- DEBT-008: remove query-string token auth; header-only Bearer now enforced
- DEBT-013: add regex constraint ^[a-z0-9\-]{1,64}$ on decky_name path param
- DEBT-015: stop leaking raw exception detail to API clients; log server-side
- DEBT-016: validate search (max_length=512) and datetime params with regex

Reliability:
- DEBT-014: wrap SSE event_generator in try/except; yield error frame on failure
- DEBT-017: emit log.warning/error on DB init retry; silent failures now visible

Observability / Docs:
- DEBT-020: add 401/422 response declarations to all route decorators

Infrastructure:
- DEBT-018: add HEALTHCHECK to all 24 template Dockerfiles
- DEBT-019: add USER decnet + setcap cap_net_bind_service to all 24 Dockerfiles
- DEBT-024: bump Redis template version 7.0.12 → 7.2.7

Config:
- DEBT-012: validate DECNET_API_PORT and DECNET_WEB_PORT range (1-65535)

Code quality:
- DEBT-010: delete 22 duplicate decnet_logging.py copies; deployer injects canonical
- DEBT-022: closed as false positive (print only in module docstring)
- DEBT-009: closed as false positive (templates already use structured syslog_line)

Build:
- DEBT-025: generate requirements.lock via pip freeze

Testing:
- DEBT-005/006/007: comprehensive test suite added across tests/api/
- conftest: in-memory SQLite + StaticPool + monkeypatched session_factory
- fuzz mark added; default run excludes fuzz; -n logical parallelism

DEBT.md updated: 23/25 items closed; DEBT-011 (Alembic) and DEBT-023 (digest pinning) remain

decnet/web/router/auth/api_change_pass.py

@@ -9,7 +9,11 @@ from decnet.web.db.models import ChangePasswordRequest
 router = APIRouter()
 
 
-@router.post("/auth/change-password", tags=["Authentication"])
+@router.post(
+    "/auth/change-password",
+    tags=["Authentication"],
+    responses={401: {"description": "Invalid or expired token / wrong old password"}, 422: {"description": "Validation error"}},
+)
 async def change_password(request: ChangePasswordRequest, current_user: str = Depends(get_current_user)) -> dict[str, str]:
     _user: Optional[dict[str, Any]] = await repo.get_user_by_uuid(current_user)
     if not _user or not verify_password(request.old_password, _user["password_hash"]):

decnet/web/router/auth/api_login.py

@@ -14,7 +14,12 @@ from decnet.web.db.models import LoginRequest, Token
 router = APIRouter()
 
 
-@router.post("/auth/login", response_model=Token, tags=["Authentication"])
+@router.post(
+    "/auth/login",
+    response_model=Token,
+    tags=["Authentication"],
+    responses={401: {"description": "Incorrect username or password"}, 422: {"description": "Validation error"}},
+)
 async def login(request: LoginRequest) -> dict[str, Any]:
     _user: Optional[dict[str, Any]] = await repo.get_user_by_username(request.username)
     if not _user or not verify_password(request.password, _user["password_hash"]):