refactor: move init_db() to db.py

Phase 1.1 - Database-Logik konsolidieren

ÄNDERUNGEN:
- init_db() von main.py nach db.py verschoben
- main.py importiert init_db von db
- startup_event() ruft db.init_db() auf
- Keine funktionalen Änderungen

DATEIEN:
- backend/db.py: +60 Zeilen (init_db Funktion)
- backend/main.py: -48 Zeilen (init_db entfernt, import hinzugefügt)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/db.py

@@ -148,3 +148,48 @@ def execute_write(conn, query: str, params: tuple = ()) -> None:
     """
     with get_cursor(conn) as cur:
         cur.execute(query, params)
+
+
+def init_db():
+    """
+    Initialize database with required data.
+
+    Ensures critical data exists (e.g., pipeline master prompt).
+    Safe to call multiple times - checks before inserting.
+    Called automatically on app startup.
+    """
+    try:
+        with get_db() as conn:
+            cur = get_cursor(conn)
+
+            # Check if table exists first
+            cur.execute("""
+                SELECT EXISTS (
+                    SELECT FROM information_schema.tables
+                    WHERE table_schema = 'public'
+                    AND table_name = 'ai_prompts'
+                ) as table_exists
+            """)
+            if not cur.fetchone()['table_exists']:
+                print("⚠️  ai_prompts table doesn't exist yet - skipping pipeline prompt creation")
+                return
+
+            # Ensure "pipeline" master prompt exists
+            cur.execute("SELECT COUNT(*) as count FROM ai_prompts WHERE slug='pipeline'")
+            if cur.fetchone()['count'] == 0:
+                cur.execute("""
+                    INSERT INTO ai_prompts (slug, name, description, template, active, sort_order)
+                    VALUES (
+                        'pipeline',
+                        'Mehrstufige Gesamtanalyse',
+                        'Master-Schalter für die gesamte Pipeline. Deaktiviere diese Analyse, um die Pipeline komplett zu verstecken.',
+                        'PIPELINE_MASTER',
+                        true,
+                        -10
+                    )
+                """)
+                conn.commit()
+                print("✓ Pipeline master prompt created")
+    except Exception as e:
+        print(f"⚠️  Could not create pipeline prompt: {e}")
+        # Don't fail startup - prompt can be created manually

backend/main.py

@@ -15,7 +15,7 @@ from slowapi.util import get_remote_address
 from slowapi.errors import RateLimitExceeded
 from starlette.requests import Request
 
-from db import get_db, get_cursor, r2d
+from db import get_db, get_cursor, r2d, init_db
 
 DATA_DIR   = Path(os.getenv("DATA_DIR",   "./data"))
 PHOTOS_DIR = Path(os.getenv("PHOTOS_DIR", "./photos"))
@@ -49,46 +49,6 @@ async def startup_event():
         print(f"⚠️  init_db() failed (non-fatal): {e}")
         # Don't crash on startup - pipeline prompt can be created manually
 
-def init_db():
-    """Initialize database - Schema is loaded by startup.sh"""
-    # Schema loading and migration handled by startup.sh
-    # This function kept for backwards compatibility
-
-    # Ensure "pipeline" master prompt exists
-    try:
-        with get_db() as conn:
-            cur = get_cursor(conn)
-            # Check if table exists first
-            cur.execute("""
-                SELECT EXISTS (
-                    SELECT FROM information_schema.tables
-                    WHERE table_schema = 'public'
-                    AND table_name = 'ai_prompts'
-                ) as table_exists
-            """)
-            if not cur.fetchone()['table_exists']:
-                print("⚠️  ai_prompts table doesn't exist yet - skipping pipeline prompt creation")
-                return
-
-            cur.execute("SELECT COUNT(*) as count FROM ai_prompts WHERE slug='pipeline'")
-            if cur.fetchone()['count'] == 0:
-                cur.execute("""
-                    INSERT INTO ai_prompts (slug, name, description, template, active, sort_order)
-                    VALUES (
-                        'pipeline',
-                        'Mehrstufige Gesamtanalyse',
-                        'Master-Schalter für die gesamte Pipeline. Deaktiviere diese Analyse, um die Pipeline komplett zu verstecken.',
-                        'PIPELINE_MASTER',
-                        true,
-                        -10
-                    )
-                """)
-                conn.commit()
-                print("✓ Pipeline master prompt created")
-    except Exception as e:
-        print(f"⚠️  Could not create pipeline prompt: {e}")
-        # Don't fail startup - prompt can be created manually
-
 # ── Helper: get profile_id from header ───────────────────────────────────────
 def get_pid(x_profile_id: Optional[str] = Header(default=None)) -> str:
     """Get profile_id - from header for legacy endpoints."""