fix(decks): align due card count with study screen limits

The deck list was showing all due cards without applying the
newCardsPerDay limit or review card limit (100), causing a mismatch
with the actual number of cards available in the study screen.

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

7 files changed, 92 insertions, 2 deletions

diff --git a/src/server/repositories/card.test.ts b/src/server/repositories/card.test.ts
index 1ed31c7..21e5485 100644
--- a/src/server/repositories/card.test.ts
+++ b/src/server/repositories/card.test.ts
@@ -112,6 +112,8 @@ function createMockCardRepo(): CardRepository {
 		softDeleteByNoteId: vi.fn(),
 		findDueCards: vi.fn(),
 		countDueCards: vi.fn(),
+		countDueNewCards: vi.fn(),
+		countDueReviewCards: vi.fn(),
 		findDueCardsWithNoteData: vi.fn(),
 		findDueCardsForStudy: vi.fn(),
 		findDueNewCardsForStudy: vi.fn(),
diff --git a/src/server/repositories/card.ts b/src/server/repositories/card.ts
index f546922..d382f4d 100644
--- a/src/server/repositories/card.ts
+++ b/src/server/repositories/card.ts
@@ -221,6 +221,38 @@ export const cardRepository: CardRepository = {
 		return result[0]?.count ?? 0;
 	},
 
+	async countDueNewCards(deckId: string, now: Date): Promise<number> {
+		const boundary = getEndOfStudyDayBoundary(now);
+		const result = await db
+			.select({ count: sql<number>`count(*)::int` })
+			.from(cards)
+			.where(
+				and(
+					eq(cards.deckId, deckId),
+					isNull(cards.deletedAt),
+					lt(cards.due, boundary),
+					eq(cards.state, CardState.New),
+				),
+			);
+		return result[0]?.count ?? 0;
+	},
+
+	async countDueReviewCards(deckId: string, now: Date): Promise<number> {
+		const boundary = getEndOfStudyDayBoundary(now);
+		const result = await db
+			.select({ count: sql<number>`count(*)::int` })
+			.from(cards)
+			.where(
+				and(
+					eq(cards.deckId, deckId),
+					isNull(cards.deletedAt),
+					lt(cards.due, boundary),
+					ne(cards.state, CardState.New),
+				),
+			);
+		return result[0]?.count ?? 0;
+	},
+
 	async findDueCardsWithNoteData(
 		deckId: string,
 		now: Date,
diff --git a/src/server/repositories/types.ts b/src/server/repositories/types.ts
index 47fb68f..4042daf 100644
--- a/src/server/repositories/types.ts
+++ b/src/server/repositories/types.ts
@@ -168,6 +168,8 @@ export interface CardRepository {
 		now: Date,
 		limit: number,
 	): Promise<CardForStudy[]>;
+	countDueNewCards(deckId: string, now: Date): Promise<number>;
+	countDueReviewCards(deckId: string, now: Date): Promise<number>;
 	updateFSRSFields(
 		id: string,
 		deckId: string,
diff --git a/src/server/routes/cards.test.ts b/src/server/routes/cards.test.ts
index 2179720..4595e28 100644
--- a/src/server/routes/cards.test.ts
+++ b/src/server/routes/cards.test.ts
@@ -26,6 +26,8 @@ function createMockCardRepo(): CardRepository {
 		softDeleteByNoteId: vi.fn(),
 		findDueCards: vi.fn(),
 		countDueCards: vi.fn(),
+		countDueNewCards: vi.fn(),
+		countDueReviewCards: vi.fn(),
 		findDueCardsWithNoteData: vi.fn(),
 		findDueCardsForStudy: vi.fn(),
 		findDueNewCardsForStudy: vi.fn(),
diff --git a/src/server/routes/decks.test.ts b/src/server/routes/decks.test.ts
index d48e494..d0854c1 100644
--- a/src/server/routes/decks.test.ts
+++ b/src/server/routes/decks.test.ts
@@ -6,6 +6,7 @@ import type {
 	CardRepository,
 	Deck,
 	DeckRepository,
+	ReviewLogRepository,
 } from "../repositories/index.js";
 import { createDecksRouter } from "./decks.js";
 
@@ -31,6 +32,8 @@ function createMockCardRepo(): CardRepository {
 		softDeleteByNoteId: vi.fn(),
 		findDueCards: vi.fn(),
 		countDueCards: vi.fn().mockResolvedValue(0),
+		countDueNewCards: vi.fn().mockResolvedValue(0),
+		countDueReviewCards: vi.fn().mockResolvedValue(0),
 		findDueCardsWithNoteData: vi.fn(),
 		findDueCardsForStudy: vi.fn(),
 		findDueNewCardsForStudy: vi.fn(),
@@ -39,6 +42,13 @@ function createMockCardRepo(): CardRepository {
 	};
 }
 
+function createMockReviewLogRepo(): ReviewLogRepository {
+	return {
+		create: vi.fn(),
+		countTodayNewCardReviews: vi.fn().mockResolvedValue(0),
+	};
+}
+
 const JWT_SECRET = process.env.JWT_SECRET || "test-secret";
 
 async function createTestToken(userId: string): Promise<string> {
@@ -82,15 +92,18 @@ describe("GET /api/decks", () => {
 	let app: Hono;
 	let mockDeckRepo: ReturnType<typeof createMockDeckRepo>;
 	let mockCardRepo: ReturnType<typeof createMockCardRepo>;
+	let mockReviewLogRepo: ReturnType<typeof createMockReviewLogRepo>;
 	let authToken: string;
 
 	beforeEach(async () => {
 		vi.clearAllMocks();
 		mockDeckRepo = createMockDeckRepo();
 		mockCardRepo = createMockCardRepo();
+		mockReviewLogRepo = createMockReviewLogRepo();
 		const decksRouter = createDecksRouter({
 			deckRepo: mockDeckRepo,
 			cardRepo: mockCardRepo,
+			reviewLogRepo: mockReviewLogRepo,
 		});
 		app = new Hono();
 		app.onError(errorHandler);
@@ -142,15 +155,18 @@ describe("POST /api/decks", () => {
 	let app: Hono;
 	let mockDeckRepo: ReturnType<typeof createMockDeckRepo>;
 	let mockCardRepo: ReturnType<typeof createMockCardRepo>;
+	let mockReviewLogRepo: ReturnType<typeof createMockReviewLogRepo>;
 	let authToken: string;
 
 	beforeEach(async () => {
 		vi.clearAllMocks();
 		mockDeckRepo = createMockDeckRepo();
 		mockCardRepo = createMockCardRepo();
+		mockReviewLogRepo = createMockReviewLogRepo();
 		const decksRouter = createDecksRouter({
 			deckRepo: mockDeckRepo,
 			cardRepo: mockCardRepo,
+			reviewLogRepo: mockReviewLogRepo,
 		});
 		app = new Hono();
 		app.onError(errorHandler);
@@ -255,15 +271,18 @@ describe("GET /api/decks/:id", () => {
 	let app: Hono;
 	let mockDeckRepo: ReturnType<typeof createMockDeckRepo>;
 	let mockCardRepo: ReturnType<typeof createMockCardRepo>;
+	let mockReviewLogRepo: ReturnType<typeof createMockReviewLogRepo>;
 	let authToken: string;
 
 	beforeEach(async () => {
 		vi.clearAllMocks();
 		mockDeckRepo = createMockDeckRepo();
 		mockCardRepo = createMockCardRepo();
+		mockReviewLogRepo = createMockReviewLogRepo();
 		const decksRouter = createDecksRouter({
 			deckRepo: mockDeckRepo,
 			cardRepo: mockCardRepo,
+			reviewLogRepo: mockReviewLogRepo,
 		});
 		app = new Hono();
 		app.onError(errorHandler);
@@ -325,15 +344,18 @@ describe("PUT /api/decks/:id", () => {
 	let app: Hono;
 	let mockDeckRepo: ReturnType<typeof createMockDeckRepo>;
 	let mockCardRepo: ReturnType<typeof createMockCardRepo>;
+	let mockReviewLogRepo: ReturnType<typeof createMockReviewLogRepo>;
 	let authToken: string;
 
 	beforeEach(async () => {
 		vi.clearAllMocks();
 		mockDeckRepo = createMockDeckRepo();
 		mockCardRepo = createMockCardRepo();
+		mockReviewLogRepo = createMockReviewLogRepo();
 		const decksRouter = createDecksRouter({
 			deckRepo: mockDeckRepo,
 			cardRepo: mockCardRepo,
+			reviewLogRepo: mockReviewLogRepo,
 		});
 		app = new Hono();
 		app.onError(errorHandler);
@@ -455,15 +477,18 @@ describe("DELETE /api/decks/:id", () => {
 	let app: Hono;
 	let mockDeckRepo: ReturnType<typeof createMockDeckRepo>;
 	let mockCardRepo: ReturnType<typeof createMockCardRepo>;
+	let mockReviewLogRepo: ReturnType<typeof createMockReviewLogRepo>;
 	let authToken: string;
 
 	beforeEach(async () => {
 		vi.clearAllMocks();
 		mockDeckRepo = createMockDeckRepo();
 		mockCardRepo = createMockCardRepo();
+		mockReviewLogRepo = createMockReviewLogRepo();
 		const decksRouter = createDecksRouter({
 			deckRepo: mockDeckRepo,
 			cardRepo: mockCardRepo,
+			reviewLogRepo: mockReviewLogRepo,
 		});
 		app = new Hono();
 		app.onError(errorHandler);
diff --git a/src/server/routes/decks.ts b/src/server/routes/decks.ts
index 2e170db..6a24c66 100644
--- a/src/server/routes/decks.ts
+++ b/src/server/routes/decks.ts
@@ -7,20 +7,25 @@ import {
 	cardRepository,
 	type DeckRepository,
 	deckRepository,
+	type ReviewLogRepository,
+	reviewLogRepository,
 } from "../repositories/index.js";
 import { createDeckSchema, updateDeckSchema } from "../schemas/index.js";
 
 export interface DeckDependencies {
 	deckRepo: DeckRepository;
 	cardRepo: CardRepository;
+	reviewLogRepo: ReviewLogRepository;
 }
 
 const deckIdParamSchema = z.object({
 	id: z.uuid(),
 });
 
+const REVIEW_CARDS_LIMIT = 100;
+
 export function createDecksRouter(deps: DeckDependencies) {
-	const { deckRepo, cardRepo } = deps;
+	const { deckRepo, cardRepo, reviewLogRepo } = deps;
 
 	return new Hono()
 		.use("*", authMiddleware)
@@ -30,7 +35,26 @@ export function createDecksRouter(deps: DeckDependencies) {
 			const now = new Date();
 			const decksWithDueCount = await Promise.all(
 				decks.map(async (deck) => {
-					const dueCardCount = await cardRepo.countDueCards(deck.id, now);
+					const [dueNewCards, dueReviewCards, reviewedNewCards] =
+						await Promise.all([
+							cardRepo.countDueNewCards(deck.id, now),
+							cardRepo.countDueReviewCards(deck.id, now),
+							reviewLogRepo.countTodayNewCardReviews(deck.id, now),
+						]);
+
+					// Apply the same limits as the study screen
+					const newCardBudget = Math.max(
+						0,
+						deck.newCardsPerDay - reviewedNewCards,
+					);
+					const newCardsToStudy = Math.min(dueNewCards, newCardBudget);
+					const reviewCardsToStudy = Math.min(
+						dueReviewCards,
+						REVIEW_CARDS_LIMIT,
+					);
+
+					const dueCardCount = newCardsToStudy + reviewCardsToStudy;
+
 					return { ...deck, dueCardCount };
 				}),
 			);
@@ -93,4 +117,5 @@ export function createDecksRouter(deps: DeckDependencies) {
 export const decks = createDecksRouter({
 	deckRepo: deckRepository,
 	cardRepo: cardRepository,
+	reviewLogRepo: reviewLogRepository,
 });
diff --git a/src/server/routes/study.test.ts b/src/server/routes/study.test.ts
index aeba46b..a58ea0d 100644
--- a/src/server/routes/study.test.ts
+++ b/src/server/routes/study.test.ts
@@ -26,6 +26,8 @@ function createMockCardRepo(): CardRepository {
 		softDeleteByNoteId: vi.fn(),
 		findDueCards: vi.fn(),
 		countDueCards: vi.fn(),
+		countDueNewCards: vi.fn(),
+		countDueReviewCards: vi.fn(),
 		findDueCardsWithNoteData: vi.fn(),
 		findDueCardsForStudy: vi.fn(),
 		findDueNewCardsForStudy: vi.fn(),