feat: alerts view + created-at timestamps on decisions

Mirror cscli alerts list: new /alerts endpoint hits LAPI machine auth
with since/ip/scenario/origin filters, renders ID, scope:value, reason,
country, AS, events, decisions, created_at.

Decisions table gains a Created column derived from until - duration
(LAPI does not expose created_at on /v1/decisions). Both views format
timestamps locally and append a relative "x ago" via Intl.RelativeTimeFormat,
refreshed every 30s on the decisions view.

app/templates/_decisions.html

@@ -16,7 +16,7 @@
       <thead>
         <tr>
           <th><input type="checkbox" id="sel-all"></th>
-          <th>ID</th><th>IP / value</th><th>Scope</th><th>Type</th><th>Reason</th><th>Until</th><th>Origin</th><th></th>
+          <th>ID</th><th>IP / value</th><th>Scope</th><th>Type</th><th>Reason</th><th>Created</th><th>Until</th><th>Origin</th><th></th>
         </tr>
       </thead>
       <tbody>
@@ -28,7 +28,8 @@
           <td>{{ d.scope }}</td>
           <td>{{ d.type }}</td>
           <td>{{ d.scenario }}</td>
-          <td>{{ d.until }}</td>
+          <td><time class="ts" datetime="{{ d.created_at }}">{{ d.created_at or '—' }}</time></td>
+          <td><time class="ts" datetime="{{ d.until }}">{{ d.until }}</time></td>
           <td>{{ d.origin }}</td>
           <td>
             <button class="danger" type="button"
@@ -42,6 +43,47 @@
     </table>
   </form>
   <script>
+    (function(){
+      const RTF = new Intl.RelativeTimeFormat(undefined, { numeric: 'auto' });
+      const FMT = new Intl.DateTimeFormat(undefined, {
+        year: 'numeric', month: 'short', day: '2-digit',
+        hour: '2-digit', minute: '2-digit', second: '2-digit',
+        hour12: false
+      });
+      const UNITS = [
+        ['year',   31536000],
+        ['month',  2592000],
+        ['day',    86400],
+        ['hour',   3600],
+        ['minute', 60],
+        ['second', 1],
+      ];
+      function relative(target, now){
+        const diff = (target - now) / 1000;
+        const abs = Math.abs(diff);
+        for (const [u, s] of UNITS) {
+          if (abs >= s || u === 'second') return RTF.format(Math.round(diff / s), u);
+        }
+      }
+      function render(){
+        const now = new Date();
+        document.querySelectorAll('#decisions time.ts').forEach(t => {
+          const iso = t.getAttribute('datetime');
+          if (!iso) return;
+          const d = new Date(iso);
+          if (isNaN(d)) return;
+          t.textContent = FMT.format(d);
+          t.title = iso + '  (' + relative(d, now) + ')';
+          const small = document.createElement('small');
+          small.style.color = '#888';
+          small.style.marginLeft = '.35rem';
+          small.textContent = relative(d, now);
+          t.appendChild(small);
+        });
+      }
+      render();
+      setInterval(render, 30000);
+    })();
     (function(){
       const form = document.getElementById('bulk-form');
       const all = document.getElementById('sel-all');