feat(tools): tool interface + helpers

internal/tools/tool.go

@@ -0,0 +1,24 @@
+package tools
+
+import (
+	"context"
+	"encoding/json"
+
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/registry"
+)
+
+// Tool implements registry.Tool.
+type Tool = registry.Tool
+
+func textOK(v any) (json.RawMessage, error) {
+	return json.Marshal(v)
+}
+
+func parseArgs(raw json.RawMessage, dst any) error {
+	if len(raw) == 0 {
+		return json.Unmarshal([]byte("{}"), dst)
+	}
+	return json.Unmarshal(raw, dst)
+}
+
+func _ctx(ctx context.Context) context.Context { return ctx } // stub for future hooks