feat: add early username availability check on registration step 1

support additional teacher registration information

revise evaluation to be generic

support updating evaluation prompt in UI

refine evaluation and fix CSV download problem

add doc about how the prompt is handled

feat: add branch converstion feature

remove ui tests, keep api tests only

security: Remove production credentials from repository

feat: Add production deployment support with Supabase and Docker

revise coach prompt

revise student prompt

feat: Add database-backed prompt management system with repository pattern

feat: Add admin dashboard with stats bug fix and performance improvements

docs: Add documentation for discovering prompt IDs

docs: Fix message IDs in API documentation to show database UUIDs

fix: Add branch metadata to list conversations endpoint

docs: Clarify API documentation and add database schema reference

fix: Fix SQLite boolean bug and separate API tests from UI tests

refactor: Remove studentName/coachName from database, derive from templates

feat: Add system messages API and comprehensive API documentation