Skip the check cycle for a Floating IP already occupied by another port

The cloud is live: the address list submitted as "free" (bootstrap config
or POST /api/v1/admin/ips) can drift by the time the orchestrator claims
it, or an operator can queue an already-occupied address by mistake.
Neutron's floating-IP association is a blind "last write wins" PUT with
no conflict error to catch, so associateFIP now checks the FIP's PortID
(already fetched via GetFloatingIPByAddress) before associating, guarded
against the false-positive of the FIP already belonging to this same
validator's own port.

A match routes the address straight to a new terminal ip_queue.state
("occupied", distinct from failed/fail) via db.MarkFIPOccupied — no
retries, since Neutron won't free it on its own and requeuing would let
it be reclaimed again next tick, starving the rest of the queue — plus a
dedicated fip_occupied audit event. Resubmitting the address later (once
the conflict is resolved) resets it to queued via the existing
POST /api/v1/admin/ips resubmit path (CancelIP/ListExpiredLeases updated
to treat occupied as terminal too). admin-dashboard gets its own "занят"
badge, distinct from fail/partial/cancelled.

Rebuilt bin/{control-api,admin-dashboard,prober,validator-agent} and
bin/SHA256SUMS per docs/SETUP.md's documented build recipe, since
control-api and admin-dashboard source changed.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NeVbMVEiE7XQAkBd7HQgj6

bin/SHA256SUMS

@@ -1,4 +1,4 @@
-118e09f98944ac59593af603c04a1d5f0e7cafb6549b5a562300bc31d9c769da  control-api
-48c9b99fa88be751d9badfba8b7d80f894e326a743a90e85478f1d2251ce4ab6  validator-agent
-c7b4c2464a5974237b1f98f1565884f09b1ee91a1efadb4b8e1e7d9aaf0b9fe2  prober
-b0339b9b341d9ab2d4f6835fda5d9f927a18ed8a831ec9f24dba05624664a417  admin-dashboard
+8f2ad37b7819131a9b25eee9d35a57880c7aa233bbb741f4fd8dc0af33f6241c  control-api
+3288930ce4e09e6793048103e25991f025f71dbedced39dee9bccf821eb72a3d  validator-agent
+586cb533631dfcef2246cdb69e20777f882506755d15afe475399356c1ed2d02  prober
+4729c33a2bce584cba29a8833b0701c0a1cd98bb17bf331aabffc27c4cde940c  admin-dashboard