fix: loyalty tier crash, chat duplicate rooms, sidebar defaults

- LoyaltyPage: levelBadge() now falls back to bronze for unknown tiers
  (DB had loyalty_tier='standard' from old seed data)
- migration 040: deduplicate general chat rooms + add unique index,
  normalize loyalty_tier to bronze for non-standard values
- chat.ts: ON CONFLICT clause now targets the new partial unique index
- Sidebar: DEFAULT_GROUPS only opens 'basics' by default; bump
  localStorage key to sidebarGroups_v2 to clear stale stored state

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

src/components/layout/Sidebar.tsx

@@ -33,16 +33,16 @@ type GroupKey = 'basics' | 'prices' | 'service' | 'management' | 'settingsGroup'
 
 const DEFAULT_GROUPS: Record<GroupKey, boolean> = {
   basics: true,
-  prices: true,
-  service: true,
-  management: true,
-  settingsGroup: true,
-  devGroup: true,
+  prices: false,
+  service: false,
+  management: false,
+  settingsGroup: false,
+  devGroup: false,
 }
 
 function loadGroups(): Record<GroupKey, boolean> {
   try {
-    const stored = JSON.parse(localStorage.getItem('sidebarGroups') || '{}')
+    const stored = JSON.parse(localStorage.getItem('sidebarGroups_v2') || '{}')
     return { ...DEFAULT_GROUPS, ...stored }
   } catch {
     return { ...DEFAULT_GROUPS }
@@ -50,7 +50,7 @@ function loadGroups(): Record<GroupKey, boolean> {
 }
 
 function saveGroups(groups: Record<GroupKey, boolean>) {
-  localStorage.setItem('sidebarGroups', JSON.stringify(groups))
+  localStorage.setItem('sidebarGroups_v2', JSON.stringify(groups))
 }
 
 // ── NavItem with star ──────────────────────────────────────────────────────