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>

petrolyst-insights/assets/branding/petrolyst_wordmark_white.svg

@@ -1,5 +1,5 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="89 671 1268 103" role="img" aria-label="Petrolyst">
-<!-- Petrolyst's wordmark alone: petrolyst-ui/design/brand/02_Logo/Vector_Master/
+<!-- Petrolyst's wordmark alone: petrolyst-web/design/brand/02_Logo/Vector_Master/
      petrolyst_logo_standard_white_no_tagline.svg without the Y mark above it, paths and
      colours unchanged, the viewBox cropped to the letters. The navbar logo (superset_config.py). -->
 <g fill="#FFFFFF"><path d="M 250.0,753.0 L 250.0,767.0 L 339.0,767.0 L 339.0,764.0 L 340.0,763.0 L 340.0,757.0 L 339.0,756.0 L 339.0,752.0 L 251.0,752.0 Z" fill="#FFFFFF" fill-rule="evenodd"/>