feat(openapi): generate OpenAPI specs from TypeSpec sources

Migrate hand-written OpenAPI YAML to TypeSpec (.tsp) source files.
TypeSpec compiles to OpenAPI 3.0 YAML, enabling type-safe API definitions.

- Add typespec/ directory with api-server and fortee definitions
- Integrate TypeSpec build into `just gen` and `just build` pipelines
- Update backend handler code to match new generated type names
  (inlined error responses, separate GameType/ProblemLanguage enums)
- Regenerate frontend TypeScript types from new OpenAPI output

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

1 files changed, 119 insertions, 0 deletions

diff --git a/typespec/api-server/models.tsp b/typespec/api-server/models.tsp
new file mode 100644
index 0000000..47519be
--- /dev/null
+++ b/typespec/api-server/models.tsp
@@ -0,0 +1,119 @@
+using TypeSpec.Http;
+using TypeSpec.OpenAPI;
+
+namespace AlbatrossApi;
+
+// ---------- Error ----------
+
+model Error {
+  message: string;
+}
+
+// ---------- Error Responses ----------
+
+@error
+model UnauthorizedError {
+  @statusCode statusCode: 401;
+  @body body: Error;
+}
+
+@error
+model ForbiddenError {
+  @statusCode statusCode: 403;
+  @body body: Error;
+}
+
+@error
+model NotFoundError {
+  @statusCode statusCode: 404;
+  @body body: Error;
+}
+
+// ---------- Enums ----------
+
+enum GameType {
+  `1v1`,
+  multiplayer,
+}
+
+enum ProblemLanguage {
+  php,
+  swift,
+}
+
+enum ExecutionStatus {
+  none,
+  running,
+  success,
+  wrong_answer,
+  timeout,
+  compile_error,
+  runtime_error,
+  internal_error,
+}
+
+// ---------- Models ----------
+
+model User {
+  user_id: integer;
+  username: string;
+  display_name: string;
+  icon_path?: string;
+  is_admin: boolean;
+  label: string | null;
+}
+
+model Problem {
+  problem_id: integer;
+  title: string;
+  description: string;
+  language: ProblemLanguage;
+  sample_code: string;
+}
+
+model Game {
+  game_id: integer;
+  game_type: GameType;
+  is_public: boolean;
+  display_name: string;
+  duration_seconds: integer;
+
+  @extension("x-go-type", "int64")
+  started_at?: integer;
+
+  problem: Problem;
+  main_players: User[];
+}
+
+model LatestGameState {
+  code: string;
+  score: integer | null;
+
+  @extension("x-go-type", "int64")
+  best_score_submitted_at: integer | null;
+
+  status: ExecutionStatus;
+}
+
+model RankingEntry {
+  player: User;
+  score: integer;
+
+  @extension("x-go-type", "int64")
+  submitted_at: integer;
+
+  code: string | null;
+}
+
+model Tournament {
+  matches: TournamentMatch[];
+}
+
+model TournamentMatch {
+  game_id: integer;
+  player1?: User;
+  player2?: User;
+  player1_score?: integer;
+  player2_score?: integer;
+  winner?: integer;
+}