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/db/sqlite/database.py

@@ -7,11 +7,15 @@ from pathlib import Path
 # Sync for initialization (DDL) and async for standard queries
 
 def get_async_engine(db_path: str):
-    # aiosqlite driver for async access
-    return create_async_engine(f"sqlite+aiosqlite:///{db_path}", echo=False, connect_args={"uri": True})
+    # If it's a memory URI, don't add the extra slash that turns it into a relative file
+    prefix = "sqlite+aiosqlite:///"
+    if db_path.startswith("file:"):
+        prefix = "sqlite+aiosqlite:///"
+    return create_async_engine(f"{prefix}{db_path}", echo=False, connect_args={"uri": True})
 
 def get_sync_engine(db_path: str):
-    return create_engine(f"sqlite:///{db_path}", echo=False, connect_args={"uri": True})
+    prefix = "sqlite:///"
+    return create_engine(f"{prefix}{db_path}", echo=False, connect_args={"uri": True})
 
 def init_db(db_path: str):
     """Synchronously create all tables."""