Scan floating IPs in the background, page by page, so thousands of addresses work

The "Scan Floating IP" button failed with a client timeout: the project now
holds ~6.4k floating IPs and the scan listed them all in one unpaginated,
timeout-less Neutron request on the HTTP request context.

openstack: ListFreeFloatingIPs reads marker-based pages (fields= keeps them
small) with per-page retry/backoff on transport errors, 5xx and 429, and every
request now has a timeout (also ends hangs inside the orchestrator tick).

orchestrator: the scan is a single-flight background job on the process
context with progress (clearing/listing/enqueuing/done/error), dry_run, full
discovery before anything is enqueued, then SubmitIPs in chunks of 500 in
ascending IP order; a failed read leaves the queue untouched. The auto-cycle
gets a "scanning" phase that polls the job, so the control loop and
autoCycleMu are never held across OpenStack/DB work; it recovers after a
restart and waits for (instead of adopting) a scan started by someone else.

db: migration 0009 (indexes), paged ListIPsPage/ListRegistryPage, GROUP BY
counters, EXISTS completion check, set-based ClearAllIPs.

API: POST /admin/ips/scan -> 202 (dry_run, wait), GET /admin/ips/scan, paging
and filters on /admin/ips and /admin/registry (bare arrays without limit),
results_by_overall in /admin/status.

dashboard: scan progress panel and dry-run button, paginated /ips and
/registry with server-side filters, Overview on counters and capped lists
with progress/ETA, "select all N by filter", hx-params fix for per-row
buttons, real counts in confirmations.

Also: docs (API, USAGE, DASHBOARD, README), plan and review under
docs/changes/, bin/ rebuilt with new SHA256SUMS.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/dashboard/static/dashboard.css

@@ -559,3 +559,53 @@ textarea.autosize { overflow-y: hidden; resize: none; }
 }
 .sidebar-user-name { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .sidebar-user + .sidebar-foot { margin-top: 0; }
+
+/* ---------- scan progress, progress bars, pager, bulk selection ---------- */
+progress {
+  appearance: none; -webkit-appearance: none;
+  display: block; width: 100%; height: 8px;
+  border: 0; border-radius: var(--radius-sm);
+  background: var(--surface-alt); color: var(--accent);
+  overflow: hidden;
+}
+progress::-webkit-progress-bar { background: var(--surface-alt); border-radius: var(--radius-sm); }
+progress::-webkit-progress-value { background: var(--accent); border-radius: var(--radius-sm); }
+progress::-moz-progress-bar { background: var(--accent); border-radius: var(--radius-sm); }
+/* Indeterminate (no value attribute): a sliding stripe, Firefox/Chromium. */
+progress:indeterminate { background: linear-gradient(90deg, var(--surface-alt) 0, var(--accent-soft) 40%, var(--surface-alt) 80%); background-size: 200% 100%; animation: progress-slide 1.4s linear infinite; }
+progress:indeterminate::-webkit-progress-value { background: transparent; }
+progress:indeterminate::-moz-progress-bar { background: transparent; }
+@keyframes progress-slide { from { background-position: 200% 0; } to { background-position: -200% 0; } }
+@media (prefers-reduced-motion: reduce) { progress:indeterminate { animation: none; } }
+
+.overall-progress { margin-top: 12px; font-size: 12.5px; color: var(--text-muted); }
+.overall-progress p { margin-bottom: 6px; }
+
+.scan-progress { margin-top: 16px; }
+.scan-actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 10px; }
+.scan-progress progress { margin-bottom: 10px; }
+.scan-counters { display: flex; flex-wrap: wrap; gap: 6px 22px; font-size: 12.5px; color: var(--text-muted); }
+.scan-counters dt { display: inline; }
+.scan-counters dd { display: inline; margin: 0 0 0 4px; color: var(--text); font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
+.scan-error { margin-top: 8px; padding: 8px 10px; border: 1px solid var(--danger-border); border-radius: var(--radius-xs); background: var(--danger-soft); color: var(--danger); font-size: 12.5px; }
+.btn[disabled] { opacity: .5; cursor: not-allowed; }
+
+.pager { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-top: 12px; font-size: 12.5px; color: var(--text-muted); }
+.pager-nav { display: inline-flex; align-items: center; gap: 8px; }
+.pager-page { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
+.btn.is-disabled { opacity: .4; pointer-events: none; }
+.panel > .pager { margin: 0; padding: 10px 16px; border-top: 1px solid var(--border-soft); }
+
+.bulk-bar { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
+.bulk-hint { padding: 8px 16px; font-size: 12.5px; color: var(--text-muted); border-top: 1px solid var(--border-soft); border-bottom: 1px solid var(--border-soft); background: var(--surface-alt); }
+.bulk-hint b { color: var(--text); font-family: var(--font-mono); font-weight: 500; }
+.select-all-link, .scope-all-msg, .btn-del-all { display: none; }
+#ips-form.sel-all .select-all-link { display: inline; margin-left: 10px; }
+#ips-form.scope-all .select-all-link { display: none; }
+#ips-form.scope-all .scope-all-msg { display: inline; margin-left: 10px; color: var(--warning); }
+#ips-form.scope-all .btn-del-all { display: inline-flex; }
+#ips-form.scope-all .btn-del-sel { display: none; }
+
+.queue-line { margin: 14px 0 8px; font-size: 13px; color: var(--text-muted); }
+.queue-line b { color: var(--text); font-family: var(--font-mono); font-weight: 500; }
+table.compact td, table.compact th { padding-top: 6px; padding-bottom: 6px; }