feat: polish invoice editor and viewer UI with custom NumberInput

component

- Create custom NumberInput component with increment/decrement buttons
- Add 0.25 step increments for hours and rates in invoice forms
- Implement emerald-themed styling with hover states and accessibility
- Add keyboard navigation (arrow keys) and proper ARIA support
- Condense invoice editor tax/totals section into efficient grid layout
- Update client dropdown to single-line format (name + email)
- Add fixed footer with floating action bar pattern matching business
  forms
- Redesign invoice viewer with better space utilization and visual
  hierarchy
- Maintain professional appearance and consistent design system
- Fix Next.js 15 params Promise handling across all invoice pages
- Resolve TypeScript compilation errors and type-only imports

tailwind.config.ts

@@ -52,6 +52,26 @@ export default {
           DEFAULT: "hsl(var(--card))",
           foreground: "hsl(var(--card-foreground))",
         },
+        brand: {
+          primary: "hsl(var(--brand-primary))",
+          "primary-hover": "hsl(var(--brand-primary-hover))",
+          secondary: "hsl(var(--brand-secondary))",
+          "secondary-hover": "hsl(var(--brand-secondary-hover))",
+        },
+        status: {
+          success: "hsl(var(--status-success))",
+          "success-foreground": "hsl(var(--status-success-foreground))",
+          "success-muted": "hsl(var(--status-success-muted))",
+          warning: "hsl(var(--status-warning))",
+          "warning-foreground": "hsl(var(--status-warning-foreground))",
+          "warning-muted": "hsl(var(--status-warning-muted))",
+          error: "hsl(var(--status-error))",
+          "error-foreground": "hsl(var(--status-error-foreground))",
+          "error-muted": "hsl(var(--status-error-muted))",
+          info: "hsl(var(--status-info))",
+          "info-foreground": "hsl(var(--status-info-foreground))",
+          "info-muted": "hsl(var(--status-info-muted))",
+        },
       },
       borderRadius: {
         lg: "var(--radius)",