chore(test): move vitest cache to node_modules/.cache

`pnpm install` already clears `node_modules/` (and its `.cache/`
subdir) automatically, so pinning vitest's cacheDir there gives
us free cache invalidation on every install without needing a
dedicated clean step. Matches the pattern applied in
../socket-packageurl-js, ../socket-sdk-js (#616),
../socket-cli (#1274), and ../meander.

Applied to both the main and isolated vitest configs.

Dropped `**/.cache/` from .gitignore — nothing writes to a
top-level `.cache/` anymore; the only cache consumers are now
rooted under node_modules.

Author: jdalton

.config/vitest.config.isolated.mts

@@ -14,7 +14,7 @@ const projectRoot = path.resolve(__dirname, '..')
 const toGlobPath = (pathLike: string): string => pathLike.replaceAll('\\', '/')
 
 const vitestConfigIsolated = defineConfig({
-  cacheDir: path.resolve(projectRoot, '.cache/vitest-isolated'),
+  cacheDir: path.resolve(projectRoot, 'node_modules/.cache/vitest-isolated'),
   resolve: {
     preserveSymlinks: false,
     extensions: ['.mts', '.ts', '.mjs', '.js', '.json'],

.config/vitest.config.mts

@@ -19,7 +19,7 @@ const rootPkgJson = JSON.parse(
 const toGlobPath = (pathLike: string): string => pathLike.replaceAll('\\', '/')
 
 const vitestConfig = defineConfig({
-  cacheDir: path.resolve(projectRoot, '.cache/vitest'),
+  cacheDir: path.resolve(projectRoot, 'node_modules/.cache/vitest'),
   resolve: {
     // Use 'source' export condition so @socketsecurity/lib/* imports resolve
     // to src/*.ts instead of dist/*.js. This enables proper v8 coverage

.gitignore

@@ -27,7 +27,6 @@ yarn.lock
 # ============================================================================
 # Build outputs and artifacts
 # ============================================================================
-**/.cache/
 .type-coverage/
 coverage/
 dist/