refactor: rename cmd/server to cmd/deklarix

Matches the project structure and binary name defined in the Deklarix
product spec.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

cmd/deklarix/main.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+)
+
+func main() {
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+	addr := ":" + port
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintf(w, `{"ok":true}`)
+	})
+
+	log.Printf("Deklarix server starting on %s", addr)
+	if err := http.ListenAndServe(addr, mux); err != nil {
+		log.Fatal(err)
+	}
+}