Add TypeDoc for API documentation generation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -95,6 +95,18 @@ npm run test:e2e:dev
 ```
 
 
+## Documentation
+
+Generate API documentation with [TypeDoc][typedoc]:
+
+```sh
+npm run docs
+```
+
+Output is in the `docs/` directory. Open `docs/index.html` in a
+browser to view.
+
+
 ## Build for Production
 
 ```sh
@@ -158,4 +170,5 @@ Code quality improvements assisted by [Claude Code][claude-code].
 [chartjs]: https://www.chartjs.org/
 [nodejs]: https://nodejs.org/
 [cypress]: https://www.cypress.io/
+[typedoc]: https://typedoc.org/
 [claude-code]: https://claude.ai/claude-code