feat(import): add CSV bulk import for notes

Add client-side CSV parsing and bulk import API endpoint for importing
notes from CSV files. Supports quoted fields, newlines in values, and
escaped quotes.

- New POST /api/decks/{deckId}/notes/import endpoint for bulk creation
- CSV parser with RFC 4180 compliance
- Multi-phase import modal (upload → validate → preview → import)
- Client-side validation with per-row error reporting

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

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

2 files changed, 32 insertions, 1 deletions

diff --git a/src/server/routes/notes.test.ts b/src/server/routes/notes.test.ts
index 2ca08f9..e354fa6 100644
--- a/src/server/routes/notes.test.ts
+++ b/src/server/routes/notes.test.ts
@@ -23,6 +23,7 @@ function createMockNoteRepo(): NoteRepository {
 		create: vi.fn(),
 		update: vi.fn(),
 		softDelete: vi.fn(),
+		createMany: vi.fn(),
 	};
 }
 
diff --git a/src/server/routes/notes.ts b/src/server/routes/notes.ts
index 16ffb09..ea7b0d0 100644
--- a/src/server/routes/notes.ts
+++ b/src/server/routes/notes.ts
@@ -8,7 +8,11 @@ import {
 	type NoteRepository,
 	noteRepository,
 } from "../repositories/index.js";
-import { createNoteSchema, updateNoteSchema } from "../schemas/index.js";
+import {
+	bulkCreateNotesSchema,
+	createNoteSchema,
+	updateNoteSchema,
+} from "../schemas/index.js";
 
 export interface NoteDependencies {
 	noteRepo: NoteRepository;
@@ -86,6 +90,32 @@ export function createNotesRouter(deps: NoteDependencies) {
 					}
 				},
 			)
+			// Bulk import notes
+			.post(
+				"/import",
+				zValidator("param", deckIdParamSchema),
+				zValidator("json", bulkCreateNotesSchema),
+				async (c) => {
+					const user = getAuthUser(c);
+					const { deckId } = c.req.valid("param");
+					const data = c.req.valid("json");
+
+					const deck = await deckRepo.findById(deckId, user.id);
+					if (!deck) {
+						throw Errors.notFound("Deck not found", "DECK_NOT_FOUND");
+					}
+
+					const result = await noteRepo.createMany(deckId, data.notes);
+
+					return c.json(
+						{
+							created: result.created,
+							failed: result.failed,
+						},
+						201,
+					);
+				},
+			)
 			// Get note with field values
 			.get("/:noteId", zValidator("param", noteIdParamSchema), async (c) => {
 				const user = getAuthUser(c);