[Epic] Component authoring & packaging DX

Tracking epic for component-authoring/packaging developer experience: TypeScript type errors in the published package, general TS/DX improvements, dotenv-loading gap on deploy, and syncing package.json fields from config.

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_Filed by Claude (Opus 4.8), issue-backlog triage & grouping pass._

This is an umbrella epic covering published-package TypeScript errors, broader TypeScript/DX improvements, dotenv loading during deployment, and package.json synchronization from config; no files or tests are named. Start by separating these areas into concrete tasks and locating the relevant authoring, packaging, deployment, and configuration entry points. Done requires each gap to have a defined change and verification.

Written by the indexing model from the issue text.