fix(migrate): warn on esbuild-specific config that fails under Vite 8

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_existing_vite_plus_esbuild_minify/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "migration-existing-vite-plus-esbuild-minify",
+  "packageManager": "pnpm@12.11.2",
+  "devDependencies": {
+    "vite-plus": "latest"
+  }
+}

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_existing_vite_plus_esbuild_minify/snapshots.toml

@@ -0,0 +1,12 @@
+[[case]]
+name = "migration_existing_vite_plus_esbuild_minify"
+vp = "global"
+skip-platforms = ["windows"]
+local-registry = true
+unset-env = ["VP_SKIP_INSTALL"]
+steps = [
+  { argv = ["vp", "migrate", "--no-interactive", "--no-hooks", "--no-agent", "--no-editor"], snapshot = false, comment = "Converge the project to a fully migrated Vite+ project; this pass rewrites the import and switches the minifier." },
+  { argv = ["vpt", "replace-file-content", "vite.config.ts", "minify: true", "minify: 'esbuild'"], snapshot = false, comment = "Reintroduce the Vite 7-era esbuild minify as the project's ONLY pending change." },
+  { argv = ["vp", "migrate", "--no-interactive", "--no-hooks", "--no-agent", "--no-editor"], comment = "The static minify rewrite emits no warnings, so it must mark the migration as done instead of hitting the already-using-Vite+ fast exit." },
+  { argv = ["vpt", "grep-file", "vite.config.ts", "minify: true"], comment = "The rewrite is applied to vite.config." },
+]

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_existing_vite_plus_esbuild_minify/snapshots/migration_existing_vite_plus_esbuild_minify.md

@@ -0,0 +1,35 @@
+# migration_existing_vite_plus_esbuild_minify
+
+## `vp migrate --no-interactive --no-hooks --no-agent --no-editor`
+
+Converge the project to a fully migrated Vite+ project; this pass rewrites the import and switches the minifier.
+
+
+## `vpt replace-file-content vite.config.ts 'minify: true' 'minify: '\''esbuild'\'''`
+
+Reintroduce the Vite 7-era esbuild minify as the project's ONLY pending change.
+
+
+## `vp migrate --no-interactive --no-hooks --no-agent --no-editor`
+
+The static minify rewrite emits no warnings, so it must mark the migration as done instead of hitting the already-using-Vite+ fast exit.
+
+```
+VITE+ - The Unified Toolchain for the Web
+
+● Formatting code...
+● Code formatted
+◇ Updated . to Vite+ <version>
+• Node <version>  pnpm <version>
+• Dependencies:
+    vite   → <version>
+• 1 config update applied
+```
+
+## `vpt grep-file vite.config.ts 'minify: true'`
+
+The rewrite is applied to vite.config.
+
+```
+vite.config.ts: found "minify: true"
+```

crates/vp_cli_snapshots/tests/cli_snapshots/fixtures/migration_existing_vite_plus_esbuild_minify/vite.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from 'vite';
+
+export default defineConfig({
+  build: {
+    minify: 'esbuild',
+    sourcemap: true,
+  },
+});