chore: From Flow to typescript

[armandabric]

TODOs

• [x] Pass on all files to re-introduce line break lost during the automatic conversion (to limit the diff of the PR)
• [x] Fix unit test (~jest~ vitest)
• [x] Rollback smoke test to JS files
• [ ] Remove the // @ts-expect-error: flow to TS comments
• [ ] Reconfigure ESLint (or configure Biome)
• [x] ~Reconfigure building: rollup/babel/typescrip (is babel still needed?)~ ~tsup~ tsdown
• [x] Ensure TS type are exported correctly
• [ ] Fix smoke test
• [x] Delete tserrors.txt file
• [ ] Release a new major beta version to test it
• [ ] :beers:

[ghost]

Hello @armandabric could we work on this together