feat: Implement student notes functionality for lessons, including API endpoints, database schema, and frontend UI.

services/lms-service/migrations/20260216000001_student_notes.sql

@@ -0,0 +1,17 @@
+-- Migration: Create Student Notes Table
+-- Description: Allows students to save personal notes for each lesson.
+
+CREATE TABLE IF NOT EXISTS student_notes (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    lesson_id UUID NOT NULL REFERENCES lessons(id) ON DELETE CASCADE,
+    content TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(user_id, lesson_id)
+);
+
+-- Index for faster retrieval by user
+CREATE INDEX IF NOT EXISTS idx_student_notes_user_id ON student_notes(user_id);
+-- Index for faster retrieval by lesson (useful if we ever want to see all notes for a lesson as an instructor, though not requested yet)
+CREATE INDEX IF NOT EXISTS idx_student_notes_lesson_id ON student_notes(lesson_id);