chore: upgrade TypeScript to v6 and Node types to v25

- bump typescript from ^5.9.3 to ^6.0.2
- bump @types/node from ^22.19.17 to ^25.6.0
- regenerate lockfile
- update dependency upgrade plan progress

Validation:
- npm run lint
- npm run check
- npm run build

Author: josecelano

docs/dependency-upgrade-plan.md

@@ -6,14 +6,14 @@ remaining major-version bump in a dedicated branch and PR.
 
 ## Status Overview
 
-| Package                                  | Current | Target       | Status         | Branch                              |
-| ---------------------------------------- | ------- | ------------ | -------------- | ----------------------------------- |
-| Patch / minor updates (all except below) | various | latest minor | ✅ Done        | `chore/update-dependencies-2026-04` |
-| `vite`                                   | 8.x     | 8.x          | ✅ Done        | `chore/upgrade-vite-8`              |
-| `@sveltejs/vite-plugin-svelte`           | 7.x     | 7.x          | ✅ Done        | `chore/upgrade-vite-8`              |
-| `svelte-sitemap`                         | 3.x     | 3.x          | ✅ Done        | `chore/upgrade-svelte-sitemap-3`    |
-| `typescript`                             | 5.x     | 6.x          | ⬜ Not started | —                                   |
-| `@types/node`                            | 22.x    | 25.x         | ⬜ Not started | —                                   |
+| Package                                  | Current | Target       | Status  | Branch                              |
+| ---------------------------------------- | ------- | ------------ | ------- | ----------------------------------- |
+| Patch / minor updates (all except below) | various | latest minor | ✅ Done | `chore/update-dependencies-2026-04` |
+| `vite`                                   | 8.x     | 8.x          | ✅ Done | `chore/upgrade-vite-8`              |
+| `@sveltejs/vite-plugin-svelte`           | 7.x     | 7.x          | ✅ Done | `chore/upgrade-vite-8`              |
+| `svelte-sitemap`                         | 3.x     | 3.x          | ✅ Done | `chore/upgrade-svelte-sitemap-3`    |
+| `typescript`                             | 6.x     | 6.x          | ✅ Done | `chore/upgrade-typescript-6`        |
+| `@types/node`                            | 25.x    | 25.x         | ✅ Done | `chore/upgrade-typescript-6`        |
 
 ---
 
@@ -85,10 +85,14 @@ This was a smaller, isolated change.
 
 ---
 
-## Phase 3 — TypeScript 5 → 6
+## Phase 3 — TypeScript 5 → 6 ✅
 
 TypeScript 6 is a significant release with stricter type checking.
 
+**Branch:** `chore/upgrade-typescript-6`
+
+**Result:** completed successfully. `npm run lint`, `npm run check`, and `npm run build` pass with no additional code changes required.
+
 **Steps:**
 
 1. Create branch `chore/upgrade-typescript-6`

package-lock.json

@@ -25,7 +25,7 @@
 		"@sveltejs/kit": "^2.57.1",
 		"@sveltejs/vite-plugin-svelte": "^7.0.0",
 		"@types/dateformat": "^5.0.3",
-		"@types/node": "^22.19.17",
+		"@types/node": "^25.6.0",
 		"@types/prismjs": "^1.26.6",
 		"@typescript-eslint/eslint-plugin": "^8.58.2",
 		"@typescript-eslint/parser": "^8.58.2",
@@ -48,7 +48,7 @@
 		"svelte-sitemap": "^3.1.0",
 		"tailwindcss": "^4.2.2",
 		"tsx": "^4.21.0",
-		"typescript": "^5.9.3",
+		"typescript": "^6.0.2",
 		"typescript-eslint": "^8.58.2",
 		"vite": "^8.0.8",
 		"vite-plugin-imagemin": "^0.6.1"