refactor: sjednoceni skeleton loading a animaci napric vsemi moduly

- AttendanceAdmin: full-page skeleton misto castecneho (header+filtry+karty+tabulka)
- AttendanceHistory: fond karta vzdy v DOM se skeleton behem loading (fix pozdni animace)
- Trips: skeleton odpovida realne strukture (stat cards + tabulka misto circle rows)
- ReceivedInvoices: 3 skeleton radky zvyseny na 5 (konzistence)
- ProjectDetail: notes spinner nahrazen skeleton bloky
- Settings: 2FA text "Nacitani..." nahrazen skeleton line
- Sjednoceny animation delays: 0.05/0.12 opraveny na standardni 0.1/0.15
- OffersTemplates: pridany chybejici stagger delays
- Invoices: opraveny duplicitni delays na spravny stagger
- Attendance sidebar: delay snizen na 0.1 (soucasne s hlavnim obsahem)

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

src/admin/pages/ReceivedInvoices.jsx

@@ -468,7 +468,7 @@ export default function ReceivedInvoicesProps({ statsMonth, statsYear, uploadOpe
 
           {loading && (
             <div className="admin-skeleton" style={{ gap: '1rem' }}>
-              {[0, 1, 2].map(i => (
+              {[0, 1, 2, 3, 4].map(i => (
                 <div key={i} className="admin-skeleton-row">
                   <div className="admin-skeleton-line w-1/4" />
                   <div className="admin-skeleton-line w-1/4" />