Add optional automatic check cycle (clear queue -> scan FIPs -> wait -> repeat)

An admin-controlled scenario that repeats what the operator does by hand:
clear the IP queue, scan and enqueue all free Floating IPs, wait until every
queued address reaches a terminal state (so results are in the Registry),
then wait a configurable interval and start over.

- control-api: new auto_cycle singleton table (migration 0008) holding
  enabled/interval/max-run settings and persisted phase state, so the cycle
  survives restarts; engine in orchestrator/autocycle.go driven from the
  existing loop tick with an injectable "now" for deterministic tests.
- Interval (default 1h, min 60s) and max wait (default unlimited, timeout
  outcome) are runtime settings, never hardcoded.
- The periodic fip_scan_interval_seconds scan is skipped while the cycle is
  enabled. An emptied queue mid-cycle counts as finished; stopping during
  the pause keeps the last cycle's outcome.
- API: GET/PUT /api/v1/admin/auto-cycle, POST .../start, POST .../stop.
- admin-dashboard: "Автоматический цикл" panel on /settings and an
  "Автоцикл активен" indicator on /overview.
- Tests for db, orchestrator, httpapi and dashboard; run-local-e2e.sh now
  exercises a full auto cycle; docs updated; bin/ rebuilt with refreshed
  SHA256SUMS.

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

internal/dashboard/dto.go

@@ -1,6 +1,9 @@
 package dashboard
 
-import "time"
+import (
+	"strconv"
+	"time"
+)
 
 // Wire shapes for control-api's /api/v1/admin/* surface, defined locally
 // rather than importing internal/httpapi's (unexported) DTOs or
@@ -165,3 +168,79 @@ type inboundChecksDTO struct {
 	Ports []int `json:"ports"`
 	ICMP  bool  `json:"icmp"`
 }
+
+// autoCycleDTO mirrors internal/httpapi's autoCycleDTO — the status and
+// parameters of the automatic check cycle (/api/v1/admin/auto-cycle).
+type autoCycleDTO struct {
+	Enabled           bool       `json:"enabled"`
+	IntervalSeconds   int        `json:"interval_seconds"`
+	MaxRunSeconds     int        `json:"max_run_seconds"`
+	Phase             string     `json:"phase"`
+	RunStartedAt      *time.Time `json:"run_started_at"`
+	NextRunAt         *time.Time `json:"next_run_at"`
+	LastRunStartedAt  *time.Time `json:"last_run_started_at"`
+	LastRunFinishedAt *time.Time `json:"last_run_finished_at"`
+	LastOutcome       string     `json:"last_outcome"`
+	LastError         string     `json:"last_error"`
+	LastScannedFree   int        `json:"last_scanned_free"`
+	RunsTotal         int        `json:"runs_total"`
+}
+
+// secondsToMinutes renders seconds as minutes for the settings form: a
+// whole number when divisible by 60, otherwise a decimal ("1.5").
+func secondsToMinutes(sec int) string {
+	return strconv.FormatFloat(float64(sec)/60, 'f', -1, 64)
+}
+
+// IntervalMinutes and MaxRunMinutes are used by the settings template: the
+// UI works in minutes, the API in seconds.
+func (a autoCycleDTO) IntervalMinutes() string { return secondsToMinutes(a.IntervalSeconds) }
+func (a autoCycleDTO) MaxRunMinutes() string   { return secondsToMinutes(a.MaxRunSeconds) }
+
+// PhaseLabel is the Russian description of the current phase.
+func (a autoCycleDTO) PhaseLabel() string {
+	switch a.Phase {
+	case "running":
+		return "идёт проверка"
+	case "waiting":
+		return "пауза между циклами"
+	case "idle":
+		return "ожидает запуска"
+	default:
+		return a.Phase
+	}
+}
+
+// OutcomeLabel is the Russian description of the last cycle's outcome.
+func (a autoCycleDTO) OutcomeLabel() string {
+	switch a.LastOutcome {
+	case "completed":
+		return "завершён"
+	case "no_free_ips":
+		return "нет свободных IP"
+	case "timeout":
+		return "превышено время ожидания"
+	case "error":
+		return "ошибка"
+	case "stopped":
+		return "остановлен"
+	case "":
+		return "—"
+	default:
+		return a.LastOutcome
+	}
+}
+
+// OutcomePillClass picks the pill style for the last outcome.
+func (a autoCycleDTO) OutcomePillClass() string {
+	switch a.LastOutcome {
+	case "completed":
+		return "pill-success"
+	case "no_free_ips", "timeout", "stopped":
+		return "pill-warning"
+	case "error":
+		return "pill-danger"
+	default:
+		return "pill-neutral"
+	}
+}