Create Github Actions to automatically sync TypeScript Definitions with Database

[Vaibhav978]

Is your feature request related to a problem? Please describe.
When the database schema changes, the TypeScript type definitions in each lambda function's db-types.d.ts files become out of sync. This requires manual regeneration using `kysely-codegen.

Currently, we have 4 lambda functions that each need their db-types.d.ts file updated:

• apps/backend/lambdas/donors/db-types.d.ts
• apps/backend/lambdas/expenditures/db-types.d.ts
• apps/backend/lambdas/projects/db-types.d.ts
• apps/backend/lambdas/users/db-types.d.ts

Describe the solution you'd like
Create a GitHub Action workflow that automatically regenerates database type files whenever the database schema changes. The workflow should:

1. Trigger on pull requests when database-related files are modified:

   • apps/backend/db/db_setup.sql
   • apps/backend/db/kysely-codegen.config.js

2. Run kysely-codegen to generate fresh TypeScript types

   • Copy the generated types to each lambda function's db-types.d.ts file

3. Commit changes automatically

   • Commit the updated type files back to the PR branch
   • Include a clear commit message: chore: auto-regenerate database types from schema changes
   • Co-author with the PR creator (similar to terraform-plan.yml workflow, this is more optional)

4. Verify that the generated types compile correctly

• Fail the workflow if type generation fails with clear error messages