DOCFIX-172: full-project sweep -- bundle.yaml fixes ...

magnum-dashboard had NO bindings: block at all -- a real, pre-existing bug
(confirmed via git log, present since the D-052 explicit-bindings commit,
not a regression from tonight's DOCFIX-167 work) violating this bundle's
own stated "explicit per-application blocks" discipline. Fixed with a
minimal block confirmed against the real charm-magnum-dashboard metadata
(subordinate, only a real `dashboard` endpoint -- not a copy of
octavia-dashboard's fuller shape). Also relocated two section-header
comments that visually (not functionally) misattributed to the wrong app,
and corrected a stale "11 API charms" HA-chain count to 12. 56 apps/108
relations unchanged; provider-bundle-check.py PASS throughout.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QrcJx8TUar7pYAvpGJw57A