fix: crash bugs in TeamInvoices + faster load

Bug fixes:
- TeamInvoices: add useAuth import/currentUser (invoice-create crash)
- TeamInvoices: setChartYear -> setExportYear (year-dropdown crash)
- TeamDashboard: drop redundant setState-in-effect (cascading renders)
- Companies: delete dead _UnusedClientCompanies (illegal hook calls)
- annotate intentional empty PDF-fallback catches

Load speed:
- preconnect/dns-prefetch to Supabase origin
- lazy-load heic-to in Converters: page chunk 2737KB -> 9KB
- split recharts into its own 'charts' vendor chunk

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/ProfileAvatar.jsx

@@ -0,0 +1,68 @@
+function normalizeName(value) {
+  return String(value || '').trim().toLowerCase();
+}
+
+export function resolveProfileAvatar({
+  avatarUrl = '',
+  profile = null,
+  profileId = '',
+  name = '',
+  profilesById = null,
+  profilesByName = null,
+}) {
+  if (avatarUrl) return avatarUrl;
+  if (profile?.avatar_url) return profile.avatar_url;
+  if (profileId && profilesById?.get(profileId)?.avatar_url) return profilesById.get(profileId).avatar_url;
+  const normalized = normalizeName(name || profile?.name);
+  if (normalized && profilesByName?.get(normalized)?.avatar_url) return profilesByName.get(normalized).avatar_url;
+  return '';
+}
+
+export default function ProfileAvatar({
+  profile = null,
+  profileId = '',
+  name = '',
+  avatarUrl = '',
+  profilesById = null,
+  profilesByName = null,
+  size = 32,
+  fontSize = 12,
+  fallbackBg = 'var(--accent)',
+  fallbackColor = '#000',
+  alt = '',
+  style = {},
+}) {
+  const resolvedUrl = resolveProfileAvatar({ avatarUrl, profile, profileId, name, profilesById, profilesByName });
+  const initials = String(name || profile?.name || '?')
+    .split(' ')
+    .map((part) => part[0])
+    .slice(0, 2)
+    .join('')
+    .toUpperCase();
+
+  if (resolvedUrl) {
+    return (
+      <div style={{ width: size, height: size, borderRadius: '50%', overflow: 'hidden', flexShrink: 0, ...style }}>
+        <img src={resolvedUrl} alt={alt || name || profile?.name || ''} style={{ width: '100%', height: '100%', objectFit: 'cover' }} />
+      </div>
+    );
+  }
+
+  return (
+    <div
+      style={{
+        width: size,
+        height: size,
+        borderRadius: '50%',
+        background: fallbackBg,
+        display: 'flex',
+        alignItems: 'center',
+        justifyContent: 'center',
+        flexShrink: 0,
+        ...style,
+      }}
+    >
+      <span style={{ fontSize, fontWeight: 600, color: fallbackColor, lineHeight: 1 }}>{initials || '?'}</span>
+    </div>
+  );
+}