fix: millisecond precision timestamps and correct history ordering

datetime('now') only stores to the second, making same-second events
indistinguishable. Switched all instance_history and job_runs writes
to strftime('%Y-%m-%dT%H:%M:%f', 'now') for millisecond precision.

Reverted getInstanceHistory to ORDER BY changed_at DESC, id DESC so
newest events appear at the top and instance creation (lowest id,
earliest timestamp) is always at the bottom.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/db.js

@@ -173,7 +173,8 @@ export function createInstance(data) {
        @tailscale, @andromeda, @tailscale_ip, @hardware_acceleration)
   `).run(data);
   db.prepare(
-    `INSERT INTO instance_history (vmid, field, old_value, new_value) VALUES (?, 'created', NULL, NULL)`
+    `INSERT INTO instance_history (vmid, field, old_value, new_value, changed_at)
+     VALUES (?, 'created', NULL, NULL, strftime('%Y-%m-%dT%H:%M:%f', 'now'))`
   ).run(data.vmid);
 }
 
@@ -184,12 +185,13 @@ export function updateInstance(vmid, data) {
       name=@name, state=@state, stack=@stack, vmid=@newVmid,
       atlas=@atlas, argus=@argus, semaphore=@semaphore, patchmon=@patchmon,
       tailscale=@tailscale, andromeda=@andromeda, tailscale_ip=@tailscale_ip,
-      hardware_acceleration=@hardware_acceleration, updated_at=datetime('now')
+      hardware_acceleration=@hardware_acceleration, updated_at=strftime('%Y-%m-%dT%H:%M:%f', 'now')
     WHERE vmid=@vmid
   `).run({ ...data, newVmid: data.vmid, vmid });
   const newVmid = data.vmid;
   const insertEvt = db.prepare(
-    `INSERT INTO instance_history (vmid, field, old_value, new_value) VALUES (?, ?, ?, ?)`
+    `INSERT INTO instance_history (vmid, field, old_value, new_value, changed_at)
+     VALUES (?, ?, ?, ?, strftime('%Y-%m-%dT%H:%M:%f', 'now'))`
   );
   for (const field of HISTORY_FIELDS) {
     const oldVal = String(old[field] ?? '');
@@ -227,7 +229,7 @@ export function importInstances(rows, historyRows = []) {
 
 export function getInstanceHistory(vmid) {
   return db.prepare(
-    'SELECT * FROM instance_history WHERE vmid = ? ORDER BY changed_at ASC, id ASC'
+    'SELECT * FROM instance_history WHERE vmid = ? ORDER BY changed_at DESC, id DESC'
   ).all(vmid);
 }
 
@@ -309,12 +311,14 @@ export function updateJob(id, { enabled, schedule, config }) {
 }
 
 export function createJobRun(jobId) {
-  return Number(db.prepare('INSERT INTO job_runs (job_id) VALUES (?)').run(jobId).lastInsertRowid);
+  return Number(db.prepare(
+    `INSERT INTO job_runs (job_id, started_at) VALUES (?, strftime('%Y-%m-%dT%H:%M:%f', 'now'))`
+  ).run(jobId).lastInsertRowid);
 }
 
 export function completeJobRun(runId, status, result) {
   db.prepare(`
-    UPDATE job_runs SET ended_at=datetime('now'), status=@status, result=@result WHERE id=@id
+    UPDATE job_runs SET ended_at=strftime('%Y-%m-%dT%H:%M:%f', 'now'), status=@status, result=@result WHERE id=@id
   `).run({ id: runId, status, result });
 }