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

internal/dashboard/static/dashboard.css

@@ -38,6 +38,7 @@
   --info:    #0E6FA8; --info-soft:    #DDEEF8;
   --neutral: #5B6576; --neutral-soft: #E4E8EE;
   --cancel:  #6D4FC4; --cancel-soft:  #ECE7FA;
+  --occupied: #0F7B72; --occupied-soft: #DCF3F0;
 
   --overlay: rgba(10, 14, 20, .32);
 
@@ -82,6 +83,7 @@
     --info:    #5AC0FF; --info-soft:    #10222E;
     --neutral: #A3ACBE; --neutral-soft: #1B212B;
     --cancel:  #B79CFF; --cancel-soft:  #221B3A;
+    --occupied: #4FD8C9; --occupied-soft: #102B28;
 
     --overlay: rgba(0, 0, 0, .55);
 
@@ -114,6 +116,7 @@
   --info:    #5AC0FF; --info-soft:    #10222E;
   --neutral: #A3ACBE; --neutral-soft: #1B212B;
   --cancel:  #B79CFF; --cancel-soft:  #221B3A;
+  --occupied: #4FD8C9; --occupied-soft: #102B28;
 
   --overlay: rgba(0, 0, 0, .55);
 
@@ -411,6 +414,7 @@ td.num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; colo
 .pill-warning { background: var(--warning-soft); color: var(--warning); }
 .pill-danger  { background: var(--danger-soft);  color: var(--danger); }
 .pill-cancel  { background: var(--cancel-soft);  color: var(--cancel); }
+.pill-occupied { background: var(--occupied-soft); color: var(--occupied); }
 
 /* ---------- alerts ---------- */
 .alert {