feat(triggers): add schedule trigger kind + internal scheduler

Fourth trigger kind alongside registry/git/manual. Recurring time-interval
fires driven by a new internal/scheduler tick loop (default 30s, clamped
to 5m). Goes through the same webhook.Handler.FanOutForTrigger seam as
inbound HTTP webhooks, so per-binding concurrency, outcome accounting,
and config-merge semantics are identical.

Schema: triggers.last_fired_at TEXT column (additive ALTER for existing
DBs). Scheduler persists last_fired_at BEFORE dispatch so a panicking
Match cannot wedge a tight loop; failed deploys wait one full interval
before retry — correct trade-off for a periodic refresh trigger.

Frontend: TriggerKindForm + /triggers/new + /triggers/[id] gain the
schedule kind (4-col card grid, preset chips Hourly/Daily/Weekly,
custom interval input matched to Go time.ParseDuration syntax, optional
pinned reference). /triggers/[id] surfaces "last fired" on schedule rows.
EN+RU i18n in parity.

Review fixes from go-reviewer / security-reviewer / typescript-reviewer:
- Scheduler Start/Stop wrapped in sync.Once (no goroutine leak / double-
  cancel panic on shutdown re-entry).
- shouldFire rejects sub-MinInterval as defense-in-depth against
  hand-inserted rows that bypassed Validate.
- fire() asserts trigger Kind=="schedule" before dispatching.
- Aligned isValidInterval regex across all three frontend sites; reject
  the unsupported "d" unit (Go time.ParseDuration doesn't accept it).
- formatLastFired falls back to lastFiredNever on malformed timestamps
  rather than leaking raw bytes into the UI.
- main.go scheduler closure logs per-fire deployed/errored counts.

web/src/routes/triggers/[id]/+page.svelte

@@ -21,9 +21,39 @@
 	// the type checker — server validation rejects empty ids anyway.
 	const id = $derived($page.params.id ?? '');
 
-	const KNOWN_KINDS = ['registry', 'git', 'manual'] as const;
+	const KNOWN_KINDS = ['registry', 'git', 'manual', 'schedule'] as const;
 	type KnownKind = (typeof KNOWN_KINDS)[number];
 
+	const SCHEDULE_PRESETS = [
+		{ key: 'hourly', value: '1h' },
+		{ key: 'daily', value: '24h' },
+		{ key: 'weekly', value: '168h' }
+	] as const;
+
+	function isValidInterval(s: string): boolean {
+		const trimmed = s.trim();
+		if (!trimmed) return false;
+		const single = trimmed.match(/^(\d+)\s*(s|m|h)$/i);
+		if (single) {
+			const n = parseInt(single[1], 10);
+			const unit = single[2].toLowerCase();
+			if (!Number.isFinite(n) || n <= 0) return false;
+			if (unit === 's' && n < 60) return false;
+			return true;
+		}
+		return /^([0-9]+(\.[0-9]+)?(h|m|s))+$/i.test(trimmed);
+	}
+
+	function formatLastFired(ts: string): string {
+		if (!ts) return $t('redeployTriggers.detail.lastFiredNever');
+		const d = new Date(ts);
+		// Defensive: a malformed timestamp from a future writer should
+		// not leak raw bytes into the UI. Fall back to the never-fired
+		// label rather than render an unparseable string.
+		if (Number.isNaN(d.getTime())) return $t('redeployTriggers.detail.lastFiredNever');
+		return d.toLocaleString();
+	}
+
 	let trigger = $state<RedeployTrigger | null>(null);
 	let webhook = $state<TriggerWebhook | null>(null);
 	let bindings = $state<TriggerBinding[]>([]);
@@ -56,6 +86,8 @@
 	let gitMode = $state<'push' | 'tag'>('push');
 	let gitBranch = $state('main');
 	let gitTagPattern = $state('v*');
+	let schInterval = $state('24h');
+	let schReference = $state('');
 
 	let jsonText = $state('');
 
@@ -106,6 +138,10 @@
 			case 'manual':
 				// no fields
 				break;
+			case 'schedule':
+				schInterval = typeof cfg.interval === 'string' ? cfg.interval : '24h';
+				schReference = typeof cfg.reference === 'string' ? cfg.reference : '';
+				break;
 		}
 	}
 
@@ -124,6 +160,12 @@
 					: { repo: gitRepo.trim(), mode: 'tag', tag_pattern: gitTagPattern.trim() || '*' };
 			case 'manual':
 				return {};
+			case 'schedule': {
+				const ref = schReference.trim();
+				return ref
+					? { interval: schInterval.trim(), reference: ref }
+					: { interval: schInterval.trim() };
+			}
 			default:
 				return JSON.parse(jsonText || '{}');
 		}
@@ -458,6 +500,62 @@
 					<span class="note-tag">MANUAL</span>
 					<p>{$t('redeployTriggers.form.manualNote')}</p>
 				</div>
+			{:else if trigger.kind === 'schedule'}
+				<div class="note">
+					<span class="note-tag">CRN</span>
+					<p>{$t('redeployTriggers.form.scheduleNote')}</p>
+				</div>
+				<div class="field">
+					<span class="sub-label">{$t('redeployTriggers.form.intervalPresets')}</span>
+					<div
+						class="mode-row"
+						role="radiogroup"
+						aria-label={$t('redeployTriggers.form.intervalPresets')}
+					>
+						{#each SCHEDULE_PRESETS as p (p.key)}
+							<button
+								type="button"
+								role="radio"
+								aria-checked={schInterval === p.value}
+								class="mode-chip"
+								class:active={schInterval === p.value}
+								onclick={() => (schInterval = p.value)}
+							>
+								{$t(`redeployTriggers.form.intervalPreset.${p.key}`)}
+							</button>
+						{/each}
+					</div>
+				</div>
+				<div class="field">
+					<label for="t-interval" class="sub-label">{$t('redeployTriggers.form.interval')}</label>
+					<input
+						id="t-interval"
+						type="text"
+						class="input mono"
+						class:bad={!isValidInterval(schInterval)}
+						bind:value={schInterval}
+						placeholder="24h"
+						spellcheck="false"
+						required
+					/>
+					<span class="hint">{$t('redeployTriggers.form.intervalHint')}</span>
+				</div>
+				<div class="field">
+					<label for="t-schref" class="sub-label">{$t('redeployTriggers.form.scheduleReference')}</label>
+					<input
+						id="t-schref"
+						type="text"
+						class="input mono"
+						bind:value={schReference}
+						placeholder={$t('redeployTriggers.form.scheduleReferencePlaceholder')}
+						spellcheck="false"
+					/>
+					<span class="hint">{$t('redeployTriggers.form.scheduleReferenceHint')}</span>
+				</div>
+				<div class="field schedule-status">
+					<span class="sub-label">{$t('redeployTriggers.detail.lastFired')}</span>
+					<span class="mono">{formatLastFired(trigger.last_fired_at)}</span>
+				</div>
 			{/if}
 
 			<!-- Webhook ingress toggles live in the same form so a