Ship type declarations generated from existing JSDoc

[shroy]

Problem

The package ships no type declarations — no types field in package.json and no .d.ts files. Consumers running tsc with checkJs (or plain TypeScript) get TS7016: Could not find a declaration file for module 'hooktml', and every import is implicitly any. This silently defeats type-checking for exactly the API surface where it helps most: signal() value types, hook deps arrays, and component signatures.

Downstream apps currently have to hand-maintain a local declare module "hooktml" shadow of the public API and re-diff it against the README on every version bump.

Proposal

The source is already thoroughly JSDoc-annotated, so declarations can be generated rather than written:

1. Emit declarations from the existing JSDoc:

   // tsconfig.build.json
   {
     "compilerOptions": {
       "allowJs": true,
       "declaration": true,
       "emitDeclarationOnly": true,
       "outDir": "dist/types"
     },
     "include": ["src/**/*.js"]
   }

2. Point package.json at them:

   {
     "types": "./dist/types/index.d.ts",
     "exports": {
       ".": {
         "types": "./dist/types/index.d.ts",
         "browser": "./index.browser.js",
         "node": "./index.js",
         "default": "./index.js"
       }
     }
   }

3. Add the emit step to the release/build script so the declarations can never drift from the source JSDoc.

Notes

• A few internal spots may need JSDoc tightening before the emit is clean (e.g. index.js uses a bare @type {Object} where a @typedef with a current property is needed).
• Generic-heavy signatures (signal, computed) are worth eyeballing in the emitted output — JSDoc @template usually emits fine, but these are the highest-value types in the API.
• Zero runtime impact; browser/CDN consumers are unaffected.