feat: add SPA, serve at /app/, update Dockerfile and README

- React + TanStack Router + shadcn/ui SPA under spa/
- serve spa/dist at /app/ with index.html fallback for client routing
- Dockerfile: node build stage for SPA, copy dist into runtime image
- README: document SPA, CORS_ORIGINS env var, architecture entry
- vite base set to /app/, manifest.json paths fixed

spa/src/lib/api/diary.ts

@@ -0,0 +1,70 @@
+import { z } from "zod"
+import type { DiaryEntryDto, Paginated } from "./common"
+import { diaryEntryDtoSchema, movieDtoSchema, paginatedSchema, reviewDtoSchema } from "./common"
+import { del, get, post } from "./client"
+
+export const diaryQueryParamsSchema = z.object({
+  limit: z.number().optional(),
+  offset: z.number().optional(),
+  sort_by: z.string().optional(),
+  movie_id: z.string().uuid().optional(),
+})
+export type DiaryQueryParams = z.infer<typeof diaryQueryParamsSchema>
+
+export const diaryResponseSchema = paginatedSchema(diaryEntryDtoSchema)
+export type DiaryResponse = Paginated<DiaryEntryDto>
+
+export const logReviewRequestSchema = z.object({
+  external_metadata_id: z.string().optional(),
+  manual_title: z.string().optional(),
+  manual_release_year: z.number().optional(),
+  manual_director: z.string().optional(),
+  rating: z.number(),
+  comment: z.string().optional(),
+  watched_at: z.string(),
+})
+export type LogReviewRequest = z.infer<typeof logReviewRequestSchema>
+
+export const feedEntryDtoSchema = z.object({
+  movie: movieDtoSchema,
+  review: reviewDtoSchema,
+  user_id: z.string().uuid(),
+  user_email: z.string(),
+  user_display_name: z.string(),
+})
+export type FeedEntryDto = z.infer<typeof feedEntryDtoSchema>
+
+export const activityFeedQueryParamsSchema = z.object({
+  limit: z.number().optional(),
+  offset: z.number().optional(),
+  sort_by: z.string().optional(),
+})
+export type ActivityFeedQueryParams = z.infer<typeof activityFeedQueryParamsSchema>
+
+export const activityFeedResponseSchema = paginatedSchema(feedEntryDtoSchema)
+export type ActivityFeedResponse = Paginated<FeedEntryDto>
+
+export const exportQueryParamsSchema = z.object({
+  format: z.string().optional(),
+})
+export type ExportQueryParams = z.infer<typeof exportQueryParamsSchema>
+
+export function getDiary(params?: DiaryQueryParams) {
+  return get<DiaryResponse>("/diary", params)
+}
+
+export function logReview(data: LogReviewRequest) {
+  return post("/reviews", data)
+}
+
+export function deleteReview(id: string) {
+  return del(`/reviews/${id}`)
+}
+
+export function getActivityFeed(params?: ActivityFeedQueryParams) {
+  return get<ActivityFeedResponse>("/activity-feed", params)
+}
+
+export function exportDiary(params?: ExportQueryParams) {
+  return get<Blob>("/diary/export", params)
+}