Phase 4: Income API and page

- Add FrequencyCalculator static utility (all 9 frequency multipliers)
- Add IncomesController: list, create, update, delete, reorder
- Add Income DTOs with computed Monthly/Annually fields
- Add shared TypeScript types (IncomeDto, OutgoDto, BudgetDto, ShareDto, SummaryDto)
- Add API client with Bearer token injection via setTokenProvider
- Add FrequencySelect, MoneyDisplay, BudgetNav shared components
- Add Income page: sortable table with inline editing, add/delete rows, drag-to-reorder via dnd-kit
- Wire TokenWirer in App.tsx to keep API client in sync with auth state

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

src/Budget.Client/package-lock.json

@@ -8,6 +8,9 @@
       "name": "budget-client",
       "version": "0.0.0",
       "dependencies": {
+        "@dnd-kit/core": "^6.3.1",
+        "@dnd-kit/sortable": "^10.0.0",
+        "@dnd-kit/utilities": "^3.2.2",
         "oidc-client-ts": "^3.5.0",
         "react": "^19.2.5",
         "react-dom": "^19.2.5",
@@ -268,6 +271,59 @@
         "node": ">=6.9.0"
       }
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+    "node_modules/@dnd-kit/accessibility": {
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+      "license": "MIT",
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+      "license": "MIT",
+      "dependencies": {
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+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "@dnd-kit/core": "^6.3.0",
+        "react": ">=16.8.0"
+      }
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+    "node_modules/@dnd-kit/utilities": {
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+      "resolved": "https://registry.npmjs.org/@dnd-kit/utilities/-/utilities-3.2.2.tgz",
+      "integrity": "sha512-+MKAJEOfaBe5SmV6t34p80MMKhjvUz0vRrvVJbPT0WElzaOJ/1xs+D+KDv+tD/NE5ujfrChEcshd4fLn0wpiqg==",
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+      "dependencies": {
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-      "dev": true,
-      "license": "0BSD",
-      "optional": true
+      "license": "0BSD"
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     "node_modules/type-check": {
       "version": "0.4.0",