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/SPEC.md

@@ -15,8 +15,9 @@ them in Superset with the filter column.
 - Nothing is imported into the live Superset without the owner's go-ahead (phase P3).
 
 **Datasets.** The `public.v_*` views of
-`stacks/fuel-monitoring/fuel-db/migrations/0003_bi_views.sql`, read through Trino as
-`fuel.public`.
+`stacks/fuel-monitoring/fuel-db/migrations/0003_bi_views.sql`, read from fuel-db directly (database
+`fuel`, schema `public`) as the read-only role `fuel_ro`. *Until 29 Oct 2026 Superset read them
+through Trino as `fuel.public`; Trino was removed then.*
 
 **Design and rationale** live in the fuel-monitoring corpus, in
 `.context/plans/2026-10-24-fuel-db-baseline-dashboard.md`:
@@ -223,7 +224,7 @@ fleet map.
 
 ## 5. Datasets and filter mapping
 
-Physical datasets, one per `public.v_*` view on Trino `fuel.public`, plus one virtual dataset
+Physical datasets, one per `public.v_*` view in fuel-db's `public` schema, plus one virtual dataset
 *(P2)*. `coverage_detail` adds two columns to `v_coverage`:
 - `lane_name`, the lane without its sort number, which read as a count;
 - `amount`, a stock interval's delivered litres (from its opening visit up to its closing visit,
@@ -280,8 +281,8 @@ output:
   - fixed native-filter ids (`NATIVE_FILTER-site`, `NATIVE_FILTER-period`) and tab ids
     (`TAB-fleet`, `TAB-site`, `TAB-summary`, …);
   - `label_colors` for the four statuses;
-  - every view column, from `columns.tsv` (a snapshot of Trino's `information_schema`);
-  - the existing "Fuel (Trino)" database UUID, which differs per instance:
+  - every view column, from `columns.tsv` (a snapshot of PostgreSQL's catalog);
+  - the existing "Fuel" database UUID, which differs per instance:
     `import_bundle.py --show-database` prints it.
   - Before writing, it checks that every column a chart or filter uses exists in its dataset,
     that every chart in a Site filter's scope has `site_label`, that the fleet map's iframe