fix: include source files in published package for IDE navigation (#40)

Declaration maps reference `../../src/` but source files were excluded
from the npm package. Adding `"./src/"` to the files field enables IDE
"Go to Definition" to navigate to actual TypeScript source instead of
.d.ts type declarations. Zero impact on app bundle size — bundlers
resolve imports via `exports`/`main`/`module` to compiled JS in dist/.

Author: amilz

clients/js/package.json

@@ -19,7 +19,8 @@
     },
     "files": [
         "./dist/src",
-        "./dist/types"
+        "./dist/types",
+        "./src/"
     ],
     "scripts": {
         "build": "rimraf dist && tsup && tsc -p ./tsconfig.declarations.json",