fix(db): avoid repeated sqlite schema initialization

services/shared/sql_init.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import threading
 import time
 
 from sqlalchemy import inspect, text
@@ -10,6 +11,10 @@ from services.shared.schema_migrations import schema_management_mode, validate_s
 from services.shared.sql_models import Base
 
 
+_SCHEMA_INIT_LOCK = threading.Lock()
+_SCHEMA_INITIALIZED = False
+
+
 def _table_columns(inspector, table_name: str) -> set[str]:
     return {item["name"] for item in inspector.get_columns(table_name)}
 
@@ -588,15 +593,23 @@ def _apply_runtime_schema_compatibility() -> None:
 
 
 def init_sql_schema() -> None:
-    if schema_management_mode() == "migrations":
-        validate_schema_migrations_applied()
+    global _SCHEMA_INITIALIZED
+    if _SCHEMA_INITIALIZED:
         return
-    Base.metadata.create_all(bind=engine)
-    for attempt in range(5):
-        try:
-            _apply_runtime_schema_compatibility()
+    with _SCHEMA_INIT_LOCK:
+        if _SCHEMA_INITIALIZED:
             return
-        except OperationalError as exc:
-            if "database is locked" not in str(exc).lower() or attempt >= 4:
-                raise
-            time.sleep(0.25 * (attempt + 1))
+        if schema_management_mode() == "migrations":
+            validate_schema_migrations_applied()
+            _SCHEMA_INITIALIZED = True
+            return
+        Base.metadata.create_all(bind=engine)
+        for attempt in range(5):
+            try:
+                _apply_runtime_schema_compatibility()
+                _SCHEMA_INITIALIZED = True
+                return
+            except OperationalError as exc:
+                if "database is locked" not in str(exc).lower() or attempt >= 4:
+                    raise
+                time.sleep(0.25 * (attempt + 1))