fix: entrypoint.sh set -e crash, __main__.py PostgreSQL check, cli.py seed placeholders

- entrypoint.sh: use NEEDS_INIT variable instead of exit codes (set -e was killing the script)
- __main__.py: skip db_path.exists() check when using PostgreSQL
- cli.py: use dual-backend placeholders for _seed_context (was using SQLite ? syntax)
- cli.py: use 'admin' instead of 'system' for seed updated_by (FK constraint)

app/src/ctxd/__main__.py

@@ -4,7 +4,10 @@ import sys
 
 if len(sys.argv) > 1 and sys.argv[1] in ('init', 'serve', 'project-list', 'project-create',
                                           'read', 'cat', 'edit', 'search', 'sync', 'audit',
-                                          'user-list', 'user-create', 'import-vault'):
+                                          'user-list', 'user-create', 'import-vault',
+                                          'user-set-password', 'oauth-client-create',
+                                          'oauth-client-list', 'oauth-client-revoke',
+                                          'file-list', 'file-read'):
     from ctxd.cli import cli_entry
     cli_entry()
 else:
@@ -12,7 +15,9 @@ else:
     from ctxd.server import serve_sync
 
     cfg = CtxConfig.from_home()
-    if not cfg.db_path.exists():
+    # When using PostgreSQL, the DB is external — skip the file check.
+    # When using SQLite, verify the db file exists.
+    if not cfg.use_postgres and not cfg.db_path.exists():
         print("Not initialized. Run 'ctx init' first.", file=sys.stderr)
         sys.exit(1)
     serve_sync(cfg)