fix(console): fix PostgreSQL connection + add Metabase Actions guide

- Fix console/main.py: import DB_URL instead of missing DB_PATH
- Add sqlalchemy text() import for connection test
- Replace file-exists check with actual PostgreSQL connection test
- Mask password in startup banner
- Add docs/METABASE_ACTIONS.md: complete guide for data entry via
  Metabase Actions (models, forms, dashboard layout, workflows)

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

console/main.py

@@ -8,10 +8,11 @@ Usage:
 """
 
 import argparse
-import os
 import sys
 
-from console.config import VERSION, APP_NAME, APP_SUBTITLE, DB_PATH
+from sqlalchemy import text
+
+from console.config import VERSION, APP_NAME, APP_SUBTITLE, DB_URL
 
 
 def parse_args(argv=None):
@@ -27,20 +28,29 @@ def parse_args(argv=None):
     )
     parser.add_argument(
         "--db",
-        default=DB_PATH,
-        help="Path to the vehicle database (default: auto-detected)",
+        default=DB_URL,
+        help="PostgreSQL connection URL (default: from config)",
     )
     return parser.parse_args(argv)
 
 
-def _print_banner(db_path):
+def _print_banner(db_url):
     """Print a startup banner before entering terminal mode."""
+    # Mask password in display
+    display_url = db_url
+    if '@' in db_url:
+        pre_at = db_url.split('@')[0]
+        post_at = db_url.split('@', 1)[1]
+        if ':' in pre_at.split('//')[-1]:
+            user = pre_at.split('//')[-1].split(':')[0]
+            display_url = f"postgresql://{user}:****@{post_at}"
+
     border = "=" * 58
     print(border)
     print(f"  {APP_NAME} v{VERSION}")
     print(f"  {APP_SUBTITLE}")
     print(border)
-    print(f"  DB : {db_path}")
+    print(f"  DB : {display_url}")
     print(border)
     print()
 
@@ -49,20 +59,7 @@ def main(argv=None):
     """Main entry point: parse args, set up renderer, DB, and launch the app."""
     args = parse_args(argv)
 
-    db_path = args.db
-
-    # Verify the database file exists before proceeding
-    if not os.path.isfile(db_path):
-        print(
-            f"Error: Database not found at '{db_path}'.\n"
-            f"\n"
-            f"Make sure the vehicle database exists.  You can specify a\n"
-            f"custom path with the --db flag:\n"
-            f"\n"
-            f"    python -m console --db /path/to/vehicle_database.db\n",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+    db_url = args.db
 
     # Lazy imports so the module can be loaded without curses available
     # (e.g. during tests or when just checking --version).
@@ -71,9 +68,30 @@ def main(argv=None):
     from console.core.app import App
 
     # Print startup banner
-    _print_banner(db_path)
+    _print_banner(db_url)
+
+    # Test database connection before entering curses mode
+    db = Database(db_url)
+    try:
+        db._get_engine()
+        session = db._session()
+        session.execute(text("SELECT 1"))
+        session.close()
+    except Exception as e:
+        print(
+            f"Error: Cannot connect to database.\n"
+            f"\n"
+            f"  URL: {db_url}\n"
+            f"  Error: {e}\n"
+            f"\n"
+            f"Make sure PostgreSQL is running and the connection URL is correct.\n"
+            f"You can specify a custom URL with the --db flag:\n"
+            f"\n"
+            f"    python -m console --db postgresql://user:pass@host/dbname\n",
+            file=sys.stderr,
+        )
+        sys.exit(1)
 
-    db = Database(db_path)
     renderer = CursesRenderer()
     app = App(renderer=renderer, db=db)