fix(assets): remove minimax-output tracking and backup file

- Remove minimax-output/ from git (3.7MB of generation intermediates)
- Add minimax-output/ to .gitignore for future image generation
- Remove apps/web/vitest.config.ts.main.bak backup file
- Finalized demo pet images are already in apps/web/public/demo-pets/

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/vitest.config.ts.main.bak

@@ -1,20 +0,0 @@
-import { defineConfig } from "vitest/config";
-import react from "@vitejs/plugin-react";
-
-export default defineConfig({
-  plugins: [react()],
-  test: {
-    environment: "jsdom",
-    setupFiles: ["./src/test/setup.ts"],
-    globals: true,
-    coverage: {
-      provider: "v8",
-      include: ["src/**"],
-      exclude: ["src/test/**", "src/main.tsx"],
-      thresholds: {
-        lines: 50,
-        functions: 50,
-      },
-    },
-  },
-});