Note the orphaned Postgres app database

Nothing reads it since the engine moved its state to SQLite, but it still
carries the pre-cutover history and an alembic stamp naming a revision that
commit deleted — which reads like a broken migration chain and is not one.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU

NOTEPAD.md

@@ -400,6 +400,19 @@ as an em dash.
 
 ## Deferred
 
+- CHORE/OPS: the Postgres `app` database is an orphan on every installation
+  that predates 73eeec2 (2026-08-21, "Keep the engine's state in SQLite, not
+  Postgres"). Nothing reads it — the engine's database is `$DATA_DIR/fluksio.db`
+  and `docker/compose.yml` already puts `db` behind the analytics profile as
+  "Umami's database, and nothing else's" — but it still holds the pre-cutover
+  history (dev 17 MB / 43 runs, the hosted instance 15 MB / 4 runs) and is
+  stamped at `c4e8b2170f93`, a revision the squash deleted. Harmless, and
+  alarming to read: `alembic_version` says a revision that no longer exists.
+  Dump it if the history is wanted, then drop the database; on the hosted
+  instance keep the *container*, because Umami's database is in it. The `db`
+  service also still bootstraps `POSTGRES_DB=app` by default, which is what
+  recreates the confusion — `umami` would be the honest default now.
+
 - FEAT/SDK: a traced flow body — `@Flow` over a function whose calls to other
   nodes build the graph, the way Covalent's lattice does. Rejected for the first
   version with reasons in `docs/private/python-api.md` (2.5× the code, two