[v2] Deprecate Chat Interface

[nicholaspsmith]

Overview

Remove the freeform chat interface and related code after goal-based system is functional.

Part of

Memoryloop v2 Pivot - Branch 014-goal-based-learning

Deprecation Strategy

1. Build goal-based system first (Issues [v2] Database Schema: Learning Goals and Skill Trees #220-226)
2. Migrate any existing chat-derived flashcards to goals
3. Remove chat UI and routes
4. Clean up database (optional: archive old data)

Files to Remove

Pages

• app/(protected)/chat/page.tsx
• app/(protected)/chat/loading.tsx
• app/(protected)/chat/error.tsx

Components

• components/chat/ChatInterface.tsx
• components/chat/MessageList.tsx
• components/chat/MessageInput.tsx
• components/chat/GenerateFlashcardsButton.tsx
• components/chat/FallbackNotice.tsx
• components/chat/Message.tsx

API Routes

• app/api/chat/conversations/route.ts
• app/api/chat/conversations/[conversationId]/messages/route.ts

Database Operations

• lib/db/operations/conversations.ts
• lib/db/operations/messages.ts
• lib/db/operations/messages-lancedb.ts

LLM Utilities

• lib/claude/rag.ts
• lib/claude/context.ts

Database Cleanup

• Option A: Drop conversations/messages tables
• Option B: Archive to backup tables
• Recommended: Archive for 90 days, then drop

Migration Script

Create script to:

1. Find flashcards created from conversations
2. Create a "Legacy Cards" goal for each user
3. Link orphaned flashcards to this goal

Acceptance Criteria

• All goal-based features working first
• Migration script handles existing flashcards
• Chat routes return 410 Gone or redirect
• No broken links in UI
• Database cleaned up

Dependencies

• Issue [v2] Goal Creation and Skill Tree Generation #221 (Goal Creation) - MUST be complete first
• Issue [v2] Scoped Card Generation for Skill Nodes #222 (Card Generation) - MUST be complete first
• Issue [v2] Update Navigation and Home Page #226 (Navigation Update)

Related Spec

See specs/014-goal-based-learning/spec.md - FR-030