fix(datatables): give the role catalog its own row, out of reach of the config machinery

Putting it inside `custom_instance_pg_databases` was the wrong call, and it cost two ways.
The catalog serializes a generated Postgres password per role, and that row is the
operator-facing instance config, so the passwords reached `get_instance_config` and its YAML
editor — a live cluster credential in a response body, a UI field and any log of either.
Worse in the other direction: `to_settings_map` strips the catalog, so a full-row upsert of
that key writes the row back without it and the catalog is gone, while the cluster keeps every
login it described.

`custom_instance_replication_pwd` is the precedent and says exactly why — a generated secret,
written only by the server, never operator-authored, hidden so the config machinery cannot
read, rewrite or drop it. The catalog is the same thing, so it now has the same shape:
`datatable_roles`, in `HIDDEN_SETTINGS`, `PROTECTED_SETTINGS` and the agent-worker denylist.
No redaction to keep in step with three code paths, and no way for a neighbouring write to
take it out.

Two races on the same shared documents. `edit_datatable_config` read the stored data tables
outside its transaction and then wrote the whole `datatable` document, so a permissions save
committing in between was silently rolled back; it now reads under `FOR UPDATE`. And
`set_datatable_permissions` validated role ids against the catalog before opening its
transaction, so a deletion in between let it write a deleted role back — including as the
default, which every later job then fails on; it now holds the catalog lock and the settings
row across validation and write.

Completes the authorization contracts the previous commit claimed but did not finish:
`read_datatable_entry` (which it named and missed), `resolve_governing_datatable`, whose whole
job is to answer for a workspace the caller may not belong to, and
`converge_connect_grants_with`, which had not inherited its wrapper's.

Also the generic Python SDK reference: `_format_py_params` learned the bare `*` last time, but
`extract_py_functions` is a second formatter and still rendered `datatable(name, role)`, so
code written from that page passed a keyword-only argument positionally.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ti5HyeTikPMYyW8YSdiHR

cli/src/guidance/skills.gen.ts

@@ -4426,7 +4426,7 @@ def send_teams_message(conversation_id: str, text: str, success: bool = True, ca
 # 
 # Returns:
 #     DataTableClient instance
-def datatable(name: str = 'main', role: Optional[str] = None)
+def datatable(name: str = 'main', *, role: Optional[str] = None)
 
 # Get a DuckLake client for DuckDB queries.
 # 
@@ -4644,7 +4644,7 @@ def parse_sql_client_name(name: str) -> tuple[str, Optional[str]]
 # 
 #     @task(retry={"attempts": 3, "delay": 30, "multiplier": 2})
 #     async def call_api(payload: dict): ...
-def task(_func = None, path: Optional[str] = None, tag: Optional[str] = None, timeout: Optional[int] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
+def task(_func = None, *, path: Optional[str] = None, tag: Optional[str] = None, timeout: Optional[int] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
 
 # Create a task that dispatches to a separate Windmill script.
 # 
@@ -4657,7 +4657,7 @@ def task(_func = None, path: Optional[str] = None, tag: Optional[str] = None, ti
 #     @workflow
 #     async def main():
 #         data = await extract(url="https://...")
-def task_script(path: str, timeout: Optional[int] = None, tag: Optional[str] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
+def task_script(path: str, *, timeout: Optional[int] = None, tag: Optional[str] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
 
 # Create a task that dispatches to a separate Windmill flow.
 # 
@@ -4670,7 +4670,7 @@ def task_script(path: str, timeout: Optional[int] = None, tag: Optional[str] = N
 #     @workflow
 #     async def main():
 #         result = await pipeline(input=data)
-def task_flow(path: str, timeout: Optional[int] = None, tag: Optional[str] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
+def task_flow(path: str, *, timeout: Optional[int] = None, tag: Optional[str] = None, cache_ttl: Optional[int] = None, priority: Optional[int] = None, concurrency_limit: Optional[int] = None, concurrency_key: Optional[str] = None, concurrency_time_window_s: Optional[int] = None, retry: Optional[dict] = None)
 
 # Decorator marking an async function as a workflow-as-code entry point.
 # 
@@ -4735,7 +4735,7 @@ async def wait_for_approval(timeout: int = 1800, form: dict | None = None, self_
 #         ...
 # 
 #     results = await parallel(items, process, concurrency=5)
-async def parallel(items, fn, concurrency: Optional[int] = None)
+async def parallel(items, fn, *, concurrency: Optional[int] = None)
 
 # Commit Kafka offsets for a trigger with auto_commit disabled.
 #