style(design): FINDING-010 — remove ALL CAPS from dashboard card labels

Remove text-transform: uppercase and letter-spacing: 0.05em from
CollapsibleCard and SolduriCompactCard labels. Labels now render
in Title Case as written in source ("Trezorerie" not "TREZORERIE").

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/modules/reports/components/solduri/SolduriCompactCard.vue

@@ -678,8 +678,6 @@ const formatPeriodLabel = (key: string): string => {
   font-size: var(--text-xs);
   font-weight: var(--font-semibold);
   color: var(--color-text-secondary);
-  text-transform: uppercase;
-  letter-spacing: 0.05em;
 }
 
 .solduri-compact-card__value {

src/shared/components/CollapsibleCard.vue

@@ -143,8 +143,6 @@ const toggleExpanded = () => {
   color: var(--text-color-secondary);
   font-weight: var(--font-semibold);
   white-space: nowrap;
-  text-transform: uppercase;
-  letter-spacing: 0.05em;
 }
 
 /* Value */