feat(schema): make note_id and is_reversed NOT NULL

All cards now require note association - legacy card support removed.
This aligns with the note-based card architecture introduced in Phase 8.

- Add database migration for NOT NULL constraints
- Update client Dexie schema to version 3
- Remove LegacyCardItem component and legacy card handling
- Update sync schemas and type definitions
- Update all tests to use note-based cards

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/client/sync/conflict.test.ts b/src/client/sync/conflict.test.ts
index 6a10c4f..52362ff 100644
--- a/src/client/sync/conflict.test.ts
+++ b/src/client/sync/conflict.test.ts
@@ -271,6 +271,8 @@ describe("ConflictResolver", () => {
 
 			const localCard = await localCardRepository.create({
 				deckId: deck.id,
+				noteId: "test-note-id",
+				isReversed: false,
 				front: "Local Question",
 				back: "Local Answer",
 			});
@@ -278,6 +280,8 @@ describe("ConflictResolver", () => {
 			const serverCard = {
 				id: localCard.id,
 				deckId: deck.id,
+				noteId: "test-note-id",
+				isReversed: false,
 				front: "Server Question",
 				back: "Server Answer",
 				state: CardState.Review,
@@ -316,6 +320,8 @@ describe("ConflictResolver", () => {
 
 			const localCard = await localCardRepository.create({
 				deckId: deck.id,
+				noteId: "test-note-id",
+				isReversed: false,
 				front: "Local Question",
 				back: "Local Answer",
 			});
@@ -323,6 +329,8 @@ describe("ConflictResolver", () => {
 			const serverCard = {
 				id: localCard.id,
 				deckId: deck.id,
+				noteId: "test-note-id",
+				isReversed: false,
 				front: "Server Question",
 				back: "Server Answer",
 				state: CardState.New,
@@ -435,6 +443,8 @@ describe("ConflictResolver", () => {
 
 			const card = await localCardRepository.create({
 				deckId: deck.id,
+				noteId: "test-note-id",
+				isReversed: false,
 				front: "Local Question",
 				back: "Local Answer",
 			});
@@ -456,6 +466,8 @@ describe("ConflictResolver", () => {
 					{
 						id: card.id,
 						deckId: deck.id,
+						noteId: "test-note-id",
+						isReversed: false,
 						front: "Server Question",
 						back: "Server Answer",
 						state: CardState.New,