Remove Trino: Superset reads fuel-db directly as fuel_ro (PD-14)

trino/ deleted; the role trino_ro becomes fuel_ro, its password read from a
secret file at connect time; dashboards' SQL and column list for PostgreSQL;
the Compose project is renamed petrolyst, with volumes pinned to their old
names. AGENTS.md points to the architecture context. Not deployed: the next
deploy needs README's one-time steps first.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

petrolyst-insights/dashboards/atoma/import_bundle.py

@@ -15,7 +15,7 @@ the bundle are dropped; afterwards each dataset's columns are compared with the
 live view and any drift is reported (exit status 2).
 
 The database is never created or changed: the bundle's database uuid must
-already exist under the name "Fuel (Trino)", otherwise nothing is imported.
+already exist under the name "Fuel", otherwise nothing is imported.
 
 The dashboards (atoma-overview, atoma-site) get no role: admins see them in Superset, and
 the Petrolyst app shows them with guest passes (PD-12). With --embedded-out FILE
@@ -35,7 +35,7 @@ import zipfile
 
 import yaml
 
-DATABASE_NAME = "Fuel (Trino)"
+DATABASE_NAME = "Fuel"
 EMBEDDED_PREFIX = "atoma-"
 STEPS = [("datasets", "SqlaTable"), ("charts", "Slice"), ("dashboards", "Dashboard")]