Consolidate frontend REST calls with GraphQL

Replace 5 separate REST calls on home page load with a single GraphQL
query. Add homeData store that fetches posts, favorites, activities,
spotify, and auth in one request. Convert all admin mutations and
auth flows to use GraphQL. Add album images to Spotify GraphQL schema.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/graph/schema/activity.graphql

@@ -0,0 +1,14 @@
+type Activity {
+  id: ID!
+  createdAt: Time!
+  updatedAt: Time!
+  type: String!
+  name: String!
+  link: String
+}
+
+input CreateActivityInput {
+  type: String!
+  name: String!
+  link: String
+}

backend/graph/schema/auth.graphql

@@ -0,0 +1,8 @@
+input LoginInput {
+  username: String!
+  password: String!
+}
+
+type AuthPayload {
+  user: User!
+}

backend/graph/schema/favorite.graphql

@@ -0,0 +1,14 @@
+type Favorite {
+  id: ID!
+  createdAt: Time!
+  updatedAt: Time!
+  type: String!
+  name: String!
+  link: String
+}
+
+input CreateFavoriteInput {
+  type: String!
+  name: String!
+  link: String
+}

backend/graph/schema/message.graphql

@@ -0,0 +1,7 @@
+type Message {
+  id: ID!
+  content: String!
+  authorId: Int!
+  fileUrl: String
+  createdAt: Time!
+}

backend/graph/schema/post.graphql

@@ -0,0 +1,18 @@
+type Post {
+  id: ID!
+  createdAt: Time!
+  updatedAt: Time!
+  title: String!
+  author: User
+  content: String!
+}
+
+input CreatePostInput {
+  title: String!
+  content: String!
+}
+
+input UpdatePostInput {
+  title: String!
+  content: String!
+}

backend/graph/schema/rowing.graphql

@@ -0,0 +1,9 @@
+type Rowing {
+  id: ID!
+  createdAt: Time!
+  date: Time!
+  time: Int!
+  distance: Int!
+  timePer500m: Float!
+  calories: Float!
+}

backend/graph/schema/schema.graphql

@@ -0,0 +1,29 @@
+scalar Time
+
+type Query {
+  users: [User!]!
+  user(id: ID!): User
+  posts: [Post!]!
+  post(id: ID!): Post
+  activities: [Activity!]!
+  favorites: [Favorite!]!
+  rowingSessions: [Rowing!]!
+  messages: [Message!]!
+  spotifyListening: SpotifyPlaying
+  spotifyRecent: [SpotifyRecentItem!]!
+  me: User
+}
+
+type Mutation {
+  login(input: LoginInput!): AuthPayload!
+  logout: Boolean!
+  refreshToken: AuthPayload!
+  createPost(input: CreatePostInput!): Post!
+  updatePost(id: ID!, input: UpdatePostInput!): Post!
+  deletePost(id: ID!): Post!
+  createUser(input: CreateUserInput!): User!
+  deleteUser(id: ID!): User!
+  setUserAdmin(id: ID!, admin: Boolean!): User!
+  createFavorite(input: CreateFavoriteInput!): Favorite!
+  createActivity(input: CreateActivityInput!): Activity!
+}

backend/graph/schema/spotify.graphql

@@ -0,0 +1,28 @@
+type SpotifyArtist {
+  name: String!
+}
+
+type SpotifyImage {
+  url: String!
+}
+
+type SpotifyAlbum {
+  name: String!
+  images: [SpotifyImage!]!
+}
+
+type SpotifyTrack {
+  name: String!
+  artists: [SpotifyArtist!]!
+  album: SpotifyAlbum!
+}
+
+type SpotifyPlaying {
+  playing: Boolean!
+  track: SpotifyTrack
+}
+
+type SpotifyRecentItem {
+  track: SpotifyTrack!
+  playedAt: Time!
+}

backend/graph/schema/user.graphql

@@ -0,0 +1,12 @@
+type User {
+  id: ID!
+  createdAt: Time!
+  updatedAt: Time!
+  username: String!
+  admin: Boolean!
+}
+
+input CreateUserInput {
+  username: String!
+  password: String!
+}