refactor: rewrite project from Rust to Go

- Replace Axum with Chi router
- Replace sqlx with pgx for PostgreSQL
- Replace tonic/prost with grpc-go
- Replace tracing with zerolog
- Update flake.nix for Go build with protoc generation
- Preserve all existing endpoints and functionality

Stack: Chi, pgx, grpc-go, zerolog, yaml.v3

internal/api/router.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+	"github.com/go-chi/cors"
+)
+
+func NewRouter(h *Handlers) *chi.Mux {
+	r := chi.NewRouter()
+
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+	r.Use(cors.Handler(cors.Options{
+		AllowedOrigins:   []string{"*"},
+		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type"},
+		AllowCredentials: true,
+		MaxAge:           300,
+	}))
+
+	r.Get("/health", h.Health)
+
+	r.Route("/api", func(r chi.Router) {
+		r.Route("/indexers", func(r chi.Router) {
+			r.Get("/", h.ListIndexers)
+			r.Post("/search", h.SearchIndexers)
+		})
+
+		r.Route("/torrents", func(r chi.Router) {
+			r.Get("/", h.ListTorrents)
+			r.Post("/", h.AddTorrent)
+			r.Get("/{hash}", h.GetTorrent)
+			r.Delete("/{hash}", h.RemoveTorrent)
+			r.Post("/{hash}/pause", h.PauseTorrent)
+			r.Post("/{hash}/resume", h.ResumeTorrent)
+		})
+
+		r.Route("/metadata", func(r chi.Router) {
+			r.Post("/artists/search", h.SearchArtists)
+			r.Get("/artists/{id}/albums", h.GetArtistAlbums)
+		})
+
+		r.Post("/sync", h.Sync)
+
+		r.Route("/library", func(r chi.Router) {
+			r.Get("/artists", h.ListLibraryArtists)
+			r.Get("/albums", h.ListLibraryAlbums)
+			r.Get("/stats", h.LibraryStats)
+		})
+	})
+
+	return r
+}