Enrich per-event RST/VCC labels (ATR STARTS / power-up) + decode server-side

- decode_line_event adds human label: RST de-asserted->ATR STARTS,
  VCC applied->VCC ON (power-up); keep canonical event string
- Enable rst/vcc in DB decode dispatch so PWA receives decoded
  (fixes bare RESET/VCC fallback and a latent showDetail crash)
- PWA line_event_label/showDetail render decoded.label
- Bump 1.22.1, SW cache v32->v33; +1 test

frontend/index.html

@@ -416,8 +416,8 @@ const INS_NAMES = {
 // ──────────────────── UI Helpers ────────────────────
 function line_event_label(msg) {
     const d = msg.decoded;
-    if (msg.type === 'rst') return d && d.event ? 'RESET ' + (d.event === 'reset asserted' ? 'ASSERTED' : 'DE-ASSERTED') : 'RESET';
-    if (msg.type === 'vcc') return d && d.event ? 'VCC ' + (d.event === 'power applied' ? 'ON' : 'OFF') : 'VCC';
+    if (msg.type === 'rst') return d && d.label ? d.label : 'RESET';
+    if (msg.type === 'vcc') return d && d.label ? d.label : 'VCC';
     return null;
 }
 
@@ -1518,7 +1518,7 @@ function showDetail(msg, entry) {
     }
 
     if (decoded.type === 'rst' || decoded.type === 'vcc') {
-        const evName = decoded.event || (decoded.type === 'rst' ? 'reset event' : 'power event');
+        const evName = decoded.label || decoded.event || (decoded.type === 'rst' ? 'reset event' : 'power event');
         d.innerHTML = `<div class="detail-header"><strong>${ins_label(msg)}</strong><span style="color:var(--text-muted)">${detail_time_html(msg)}</span></div>
             <div class="detail-body">
                 <table>
@@ -2511,7 +2511,7 @@ function onFilterChange() {
 }
 
 // ──────────────────── Versioning ────────────────────
-const PWA_VERSION = '1.22.0';
+const PWA_VERSION = '1.22.1';
 const MIN_SERVER_VERSION = '1.0.0';
 
 function parseVersion(v) {

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simtrace-analyser-v32';
+const CACHE = 'simtrace-analyser-v33';
 
 const PRECACHE = [
     'index.html',