fix(mcp): use json.RawMessage for proper JSON unmarshaling

Add RawMessage type alias to modules/json and use it in MCP handler.
The custom RawMessage type was not implementing json.Unmarshaler,
causing parse errors when receiving MCP tool calls with params object.

🤖 Generated with Claude Code

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

modules/json/json.go

@@ -109,3 +109,7 @@ func UnmarshalHandleDoubleEncode(bs []byte, v any) error {
 	}
 	return err
 }
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay JSON decoding.
+type RawMessage = json.RawMessage

modules/structs/actions_capabilities.go

@@ -28,16 +28,27 @@ type DistroInfo struct {
 	PrettyName string `json:"pretty_name,omitempty"` // e.g., "Ubuntu 24.04 LTS"
 }
 
+// XcodeInfo holds Xcode-specific information for macOS runners
+type XcodeInfo struct {
+	Version    string   `json:"version,omitempty"`
+	Build      string   `json:"build,omitempty"`
+	SDKs       []string `json:"sdks,omitempty"`
+	Simulators []string `json:"simulators,omitempty"`
+}
+
 // RunnerCapability represents the detailed capabilities of a runner
 type RunnerCapability struct {
 	OS               string              `json:"os"`
 	Arch             string              `json:"arch"`
 	Distro           *DistroInfo         `json:"distro,omitempty"`
+	Xcode            *XcodeInfo          `json:"xcode,omitempty"`
 	Docker           bool                `json:"docker"`
 	DockerCompose    bool                `json:"docker_compose"`
 	ContainerRuntime string              `json:"container_runtime,omitempty"`
 	Shell            []string            `json:"shell,omitempty"`
 	Tools            map[string][]string `json:"tools,omitempty"`
+	BuildTools       []string            `json:"build_tools,omitempty"`
+	PackageManagers  []string            `json:"package_managers,omitempty"`
 	Features         *CapabilityFeatures `json:"features,omitempty"`
 	Limitations      []string            `json:"limitations,omitempty"`
 	Disk             *DiskInfo           `json:"disk,omitempty"`

routers/api/v2/mcp.go

@@ -22,16 +22,13 @@ import (
 	"code.gitea.io/gitea/services/context"
 )
 
-// RawMessage is a raw encoded JSON value (equivalent to encoding/json.RawMessage)
-type RawMessage []byte
-
 // MCP Protocol Types (JSON-RPC 2.0)
 
 type MCPRequest struct {
-	JSONRPC string     `json:"jsonrpc"`
-	ID      any        `json:"id"`
-	Method  string     `json:"method"`
-	Params  RawMessage `json:"params,omitempty"`
+	JSONRPC string          `json:"jsonrpc"`
+	ID      any             `json:"id"`
+	Method  string          `json:"method"`
+	Params  json.RawMessage `json:"params,omitempty"`
 }
 
 type MCPResponse struct {

templates/shared/actions/runner_edit.tmpl

@@ -174,6 +174,37 @@
 							{{end}}
 						</div>
 
+						{{if .RunnerCapabilities.Xcode}}
+						<div class="field tw-mb-3">
+							<label>Xcode</label>
+							<div>
+								{{if .RunnerCapabilities.Xcode.Version}}
+								<span class="ui small blue label">{{.RunnerCapabilities.Xcode.Version}}{{if .RunnerCapabilities.Xcode.Build}} ({{.RunnerCapabilities.Xcode.Build}}){{end}}</span>
+								{{end}}
+							</div>
+							{{if .RunnerCapabilities.Xcode.SDKs}}
+							<div class="tw-mt-2">
+								<label class="tw-text-xs" style="opacity: 0.7;">SDKs</label>
+								<div class="tw-flex tw-flex-wrap tw-gap-1">
+									{{range .RunnerCapabilities.Xcode.SDKs}}
+									<span class="ui small olive label">{{.}}</span>
+									{{end}}
+								</div>
+							</div>
+							{{end}}
+							{{if .RunnerCapabilities.Xcode.Simulators}}
+							<div class="tw-mt-2">
+								<label class="tw-text-xs" style="opacity: 0.7;">Simulators</label>
+								<div class="tw-flex tw-flex-wrap tw-gap-1">
+									{{range .RunnerCapabilities.Xcode.Simulators}}
+									<span class="ui small violet label">{{.}}</span>
+									{{end}}
+								</div>
+							</div>
+							{{end}}
+						</div>
+						{{end}}
+
 						{{if .RunnerCapabilities.Shell}}
 						<div class="field tw-mb-3">
 							<label>{{ctx.Locale.Tr "actions.runners.capabilities.shells"}}</label>
@@ -196,6 +227,28 @@
 						</div>
 						{{end}}
 
+						{{if .RunnerCapabilities.BuildTools}}
+						<div class="field tw-mb-3">
+							<label>Build Tools</label>
+							<div class="tw-flex tw-flex-wrap tw-gap-1">
+								{{range .RunnerCapabilities.BuildTools}}
+								<span class="ui small brown label">{{.}}</span>
+								{{end}}
+							</div>
+						</div>
+						{{end}}
+
+						{{if .RunnerCapabilities.PackageManagers}}
+						<div class="field tw-mb-3">
+							<label>Package Managers</label>
+							<div class="tw-flex tw-flex-wrap tw-gap-1">
+								{{range .RunnerCapabilities.PackageManagers}}
+								<span class="ui small pink label">{{.}}</span>
+								{{end}}
+							</div>
+						</div>
+						{{end}}
+
 						{{if .RunnerCapabilities.Limitations}}
 						<div class="field tw-mb-3">
 							<label>{{ctx.Locale.Tr "actions.runners.capabilities.limitations"}}</label>