feat: add admin/internal database API with CRUD, read-only query, and natural-language SQL endpoints

Add a new `/dbapi` router package providing a generic database API over `dataset`, restricted to admin sessions, admin API keys, and the internal gateway key. Includes:

- `tables.py`: list all tables and inspect table schemas
- `crud.py`: full CRUD operations (GET, POST, PATCH, DELETE) with soft-delete awareness, born-live inserts, `?include_deleted`, `.../restore`, and `?hard=true` purge
- `query.py`: validated read-only SELECT execution via sqlglot parsing, classification, and EXPLAIN dry-run; async query jobs with WebSocket streaming via `DbApiJobService`
- `nl.py`: natural-language-to-SQL conversion using the platform AI gateway with re-prompting until validation passes

Also register `DbApiJobService` and `PubSubService` in the service manager, add `DBAPI_DIR` to config data paths, and force cleartext `http://` connections to HTTP/1.1 in `curl_transport` to fix large request failures against uvicorn's HTTP/1.1-only internal gateway.

tests/unit/services/dbapi/service.py

@@ -0,0 +1,32 @@
+# retoor <retoor@molodetz.nl>
+
+from tests.conftest import run_async
+
+from devplacepy.services.dbapi.service import DbApiJobService
+
+
+def test_process_runs_select_and_writes_result(local_db):
+    svc = DbApiJobService()
+    job = {"uid": "unit-dbquery-1", "payload": {"sql": "SELECT 1 AS n"}}
+    try:
+        result = run_async(svc.process(job))
+        assert result["row_count"] == 1
+        assert result["truncated"] is False
+        assert result["result_url"].endswith("/result")
+        assert (svc.result_dir("unit-dbquery-1") / "result.json").is_file()
+    finally:
+        svc.cleanup(job)
+        assert not svc.result_dir("unit-dbquery-1").exists()
+
+
+def test_process_rejects_non_select(local_db):
+    svc = DbApiJobService()
+    job = {"uid": "unit-dbquery-2", "payload": {"sql": "DELETE FROM posts"}}
+    raised = False
+    try:
+        run_async(svc.process(job))
+    except Exception:
+        raised = True
+    finally:
+        svc.cleanup(job)
+    assert raised