Retire the Superset reader setup and the ATOMA dashboard (PD-13)

ATOMA's users use the Petrolyst app; Superset keeps admins, editors and the
app's embedded dashboards. Removed: the "ATOMA Reader" role and its rules
(petrolyst_reader.py, ReaderAccessMixin, reader.css, the head template, the
SQL-hiding patch), the atoma-reader mapping (it now maps to nothing in
Superset), the iframe allowance for the Map tab, and the "atoma" dashboard
with its Fleet/Map tab, D0 and dashboard.css. The bundle holds atoma-overview
and atoma-site only (byte-identical to before); the guest role keeps the
reader's 12 permissions in roles/atoma_guest.py. Brand files now name
petrolyst-web. SPEC marks the retired parts as history.

Checks (local): bundle checks pass; image rebuilt and healthy; import with
column drift 0 and unchanged embedding ids; the production config loads with
OAuth, embedding off, no reader hook; admin sees atoma-site with its tabs and
filter column; the app's browser tests pass 10/10. shellcheck not run (not
installed). Not deployed.

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

stacks/fuel-monitoring/superset/init.sh

@@ -12,5 +12,3 @@ superset init
 superset set-database-uri \
   --database_name "Fuel (Trino)" \
   --uri "trino://superset@trino:8080/fuel"
-# The role "ATOMA Reader", set to exactly its permissions (petrolyst-insights/roles/).
-/app/.venv/bin/python /app/petrolyst-roles/atoma_reader.py