Add browser file MCP tool

docs/framework/mcp.md

@@ -65,6 +65,13 @@ The MCP service exposes numerous tools organized by category:
 | `webview_navigate` | Navigate to URL |
 | `webview_console` | Get console logs |
 
+### Browser
+
+| Tool | Description |
+|------|-------------|
+| `browser_open_url` | Open a URL in the default system browser |
+| `browser_open_file` | Open a file with the system default application |
+
 ### Process Management
 
 | Tool | Description |

pkg/display/FEATURES.md

@@ -76,6 +76,10 @@ This document tracks the implementation of display server features that enable A
 - [x] `webview_eval` - Execute JavaScript and return result
 - [x] `webview_list` - List all webview windows
 
+### Browser
+- [x] `browser_open_url` - Open a URL in the default system browser
+- [x] `browser_open_file` - Open a file in the system default application
+
 ### Console & Errors
 - [x] `webview_console` - Get console messages (log, warn, error, info)
 - [x] `webview_errors` - Get structured JS errors with stack traces

pkg/mcp/mcp_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	core "dappco.re/go/core"
+	"forge.lthn.ai/core/gui/pkg/browser"
 	"forge.lthn.ai/core/gui/pkg/clipboard"
 	"forge.lthn.ai/core/gui/pkg/dialog"
 	"forge.lthn.ai/core/gui/pkg/events"
@@ -72,6 +73,11 @@ func TestMCP_Bad_NoServices(t *testing.T) {
 
 type manifestScreenPlatform struct{}
 
+type manifestBrowserPlatform struct {
+	lastURL  string
+	lastPath string
+}
+
 func (manifestScreenPlatform) GetAll() []screen.Screen {
 	return []screen.Screen{{
 		ID: "1", Name: "Primary", IsPrimary: true,
@@ -106,6 +112,34 @@ func TestSubsystem_Good_CallTool_LayoutSuggest(t *testing.T) {
 	assert.Contains(t, result, "left-right")
 }
 
+func (m *manifestBrowserPlatform) OpenURL(url string) error {
+	m.lastURL = url
+	return nil
+}
+
+func (m *manifestBrowserPlatform) OpenFile(path string) error {
+	m.lastPath = path
+	return nil
+}
+
+func TestSubsystem_Good_CallTool_BrowserOpenFile(t *testing.T) {
+	browserPlatform := &manifestBrowserPlatform{}
+	c := core.New(
+		core.WithService(browser.Register(browserPlatform)),
+		core.WithServiceLock(),
+	)
+	require.True(t, c.ServiceStartup(context.Background(), nil).OK)
+
+	sub := New(c)
+	server := mcp.NewServer(&mcp.Implementation{Name: "test", Version: "0.1.0"}, nil)
+	sub.RegisterTools(server)
+
+	result, err := sub.CallTool(context.Background(), "browser_open_file", map[string]any{"path": "/tmp/readme.txt"})
+	require.NoError(t, err)
+	assert.Contains(t, result, "success")
+	assert.Equal(t, "/tmp/readme.txt", browserPlatform.lastPath)
+}
+
 type aliasDialogPlatform struct {
 	last dialog.MessageDialogOptions
 }

pkg/mcp/tools_browser.go

@@ -30,8 +30,31 @@ func (s *Subsystem) browserOpenURL(_ context.Context, _ *mcp.CallToolRequest, in
 	return nil, BrowserOpenURLOutput{Success: true}, nil
 }
 
+// --- browser_open_file ---
+
+type BrowserOpenFileInput struct {
+	Path string `json:"path"`
+}
+type BrowserOpenFileOutput struct {
+	Success bool `json:"success"`
+}
+
+func (s *Subsystem) browserOpenFile(_ context.Context, _ *mcp.CallToolRequest, input BrowserOpenFileInput) (*mcp.CallToolResult, BrowserOpenFileOutput, error) {
+	r := s.core.Action("browser.openFile").Run(context.Background(), core.NewOptions(
+		core.Option{Key: "path", Value: input.Path},
+	))
+	if !r.OK {
+		if e, ok := r.Value.(error); ok {
+			return nil, BrowserOpenFileOutput{}, e
+		}
+		return nil, BrowserOpenFileOutput{}, nil
+	}
+	return nil, BrowserOpenFileOutput{Success: true}, nil
+}
+
 // --- Registration ---
 
 func (s *Subsystem) registerBrowserTools(server *mcp.Server) {
 	addTool(s, server, &mcp.Tool{Name: "browser_open_url", Description: "Open a URL in the default system browser"}, s.browserOpenURL)
+	addTool(s, server, &mcp.Tool{Name: "browser_open_file", Description: "Open a file in the system default application"}, s.browserOpenFile)
 }