feat(1d): wire oapi-codegen, generate types/server/client, add 501 stubs — tsk_Kp80nvHV2yLc

- Fix openapi.yaml: quote bearerAuth description that contained unquoted `: ` plain-scalar YAML
- Add server/api/cfg-{types,server,client}.yaml — oapi-codegen v2 config for three split outputs
- Add server/api/gen/gen.go — three //go:generate directives; run `make generate`
- Generate server/api/gen/{types,server,client}.gen.go from the contract (all 15 operations)
- Add github.com/oapi-codegen/runtime v1.4.1 to go.mod (runtime types needed by generated code)
- Add server/internal/httpapi/unimplemented.go — UnimplementedServer satisfies gen.ServerInterface;
  every method writes HTTP 501 + {code,message_zh,message_en} JSON body (no dep on task-1f apierr)
- Update server/cmd/server/main.go — mount /v1 API via gen.HandlerFromMuxWithBaseURL; keep /healthz
- Update server/Makefile — `generate` target now runs `go generate ./...`;
  add `check-generate` CI guard (regenerate + git diff --exit-code)
- Add server/internal/httpapi/unimplemented_test.go — 19 httptest cases covering all 15 API routes
  (501+body), undefined routes (404), and /healthz isolation

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

server/cmd/server/main.go

@@ -9,6 +9,9 @@ import (
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
+
+	"github.com/wangjia/pangolin/server/api/gen"
+	"github.com/wangjia/pangolin/server/internal/httpapi"
 )
 
 func main() {
@@ -27,12 +30,18 @@ func main() {
 	r.Use(middleware.Logger)
 	r.Use(middleware.Recoverer)
 
+	// Health check — outside the versioned API.
 	r.Get("/healthz", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusOK)
 		_ = json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
 	})
 
+	// Mount all /v1/... routes.  HandlerFromMuxWithBaseURL registers every route
+	// from the OpenAPI spec onto the provided chi router with the given prefix,
+	// so the router itself is the http.Handler we serve.
+	gen.HandlerFromMuxWithBaseURL(&httpapi.UnimplementedServer{}, r, "/v1")
+
 	log.Printf("pangolin server listening on %s", *addr)
 	if err := http.ListenAndServe(*addr, r); err != nil {
 		log.Fatalf("server error: %v", err)