feat(data-entry): Add unified receipt form with OCR confidence tracking

New unified receipt creation system with:
- UnifiedReceiptForm component with inline OCR preview and confidence indicators
- Compact upload zone with drag-drop and camera support
- TVA and Payment fields with dynamic add/remove
- Supplier dual-field with autocomplete and OCR hint
- Receipt form sections with collapsible auxiliary data

Backend OCR improvements:
- Add confidence_tva and confidence_payment to extraction results
- Update TVA extraction to return confidence scores
- Include TVA (15%) and payment (10%) in overall_confidence calculation

Also includes:
- CSS design system rules documentation
- Port check helper function for service scripts
- Expanded design tokens documentation in CLAUDE.md

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/settings.json

@@ -1,6 +1,6 @@
 {
   "statusLine": {
     "type": "command",
-    "command": "input=$(cat); model=$(echo \"$input\" | jq -r '.model.display_name // \"Unknown\"'); usage=$(echo \"$input\" | jq '.context_window.current_usage'); if [ \"$usage\" != \"null\" ]; then current=$(echo \"$usage\" | jq '.input_tokens + .cache_creation_input_tokens + .cache_read_input_tokens'); size=$(echo \"$input\" | jq '.context_window.context_window_size'); pct=$((current * 100 / size)); ctx=$(printf '%d%% ctx' \"$pct\"); else ctx='0% ctx'; fi; branch=$(git -c core.useBuiltinFSMonitor=false branch --show-current 2>/dev/null || echo 'no-git'); cwd=$(basename \"$(pwd)\"); printf '\\033[36m%s\\033[0m | \\033[33m%s\\033[0m | \\033[32m%s\\033[0m | \\033[35m%s\\033[0m' \"$model\" \"$ctx\" \"$branch\" \"$cwd\""
+    "command": "/home/claude/.claude/statusline.sh"
   }
 }