DOCFIX-167: bundle.yaml -- Designate reactivation + D-108 DR mechanism (gaps #6+14) ...

Adds designate/designate-bind/designate-mysql-router/designate-hacluster
(D-106, supersedes D-019) and cinder-backup/ceph-rbd-mirror (D-108) to
bundle.yaml -- the same file this repo's jumphost uses against the live
VR0/DC0 rehearsal cloud, edited with corresponding care. Every new charm's
relation/binding shape was checked against its real metadata.yaml, not
guessed: caught and fixed three mistakes this way during self-review
(designate's real endpoint is dnsaas, not public; cinder-backup is a
subordinate with no amqp relation; ceph-rbd-mirror needs ceph-local/
ceph-remote, not a single invented binding key). Corrected ceph-mon's
rbd-mirror binding from storage to replication. Documents, rather than
invents, that ceph-remote (the peer DC's ceph-mon) needs a cross-model
relation or the manual CLI flow -- D-104's per-DC-independent-controller
design means it can't be a same-bundle relation line. Deliberately does
NOT reactivate os-public-hostname in this shared bundle (pushed to a
proposed per-DC overlay instead). Bundle parses clean (56 apps, 108
relations); provider-bundle-check.py PASS, all invariants unaffected.
Not applied to any live model.

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