Followup fixes

.gitignore

@@ -17,3 +17,6 @@ docs/superpowers/
 
 # Local follow-up tracking (not shipped with the package)
 /FOLLOWUP.md
+
+# Git worktrees
+/.worktrees/

README.md

@@ -48,3 +48,44 @@ podman/docker, pgdevkit first checks (with a short timeout) whether Postgres
 is already reachable at that address and skips container management if so.
 Set `PGDEVKIT_SKIP_CONTAINER=1` to always assume it's already there and skip
 that check too.
+
+## `pgdevkit.db` — helpers for application code
+
+Install with the `db` extra: `pip install pgdevkit[db]`.
+
+- **`PostgresTableModel`** — a `pydantic.BaseModel` base class for models
+  that map 1:1 to a table row. Implement `get_table_name()` (returns
+  `(schema, table)`) and `get_primary_key()` on each model.
+- **`PgPool`** — an async connection pool keyed off
+  `{env_prefix}HOST/PORT/DB/USER/PASSWORD` env vars. Call `await pool.open()`
+  once at startup, then use `async with pool.connection() as con:`.
+- **CRUD functions** — `pg_retrieve`, `pg_retrieve_many`, `pg_insert`,
+  `pg_insert_many`, `pg_update`, `pg_update_dict`, `pg_upsert`,
+  `pg_upsert_dict`, `pg_upsert_many`, `pg_upsert_many_dict`, `pg_delete`,
+  `pg_delete_dict` — typed (`PostgresTableModel`-based) or dict-based CRUD
+  against a table, built on `psycopg` for safe identifier/value handling.
+- **`SqlLoader`** — loads and caches `.sql` files from
+  `{root}/<topic>/<name>.sql`, for keeping hand-written queries out of
+  Python source.
+
+```python
+from pgdevkit.db import PgPool, PostgresTableModel, pg_retrieve, pg_upsert
+
+class Widget(PostgresTableModel):
+    id: int
+    name: str
+
+    @staticmethod
+    def get_table_name() -> tuple[str, str]:
+        return ("public", "widget")
+
+    @staticmethod
+    def get_primary_key() -> list[str]:
+        return ["id"]
+
+pool = PgPool(env_prefix="POSTGRES_")
+await pool.open()
+async with pool.connection() as con:
+    widget = await pg_retrieve(con, Widget, {"id": 1})
+    await pg_upsert(con, Widget(id=1, name="thing"), Widget)
+```