feat: add package indexing to MCP index_revision tool

The options server's index_revision now also indexes packages when running
under nixpkgs-search, matching the CLI behavior. The packages server gets
its own index_revision tool for standalone package indexing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/mcp/server_test.go

@@ -10,6 +10,7 @@ import (
 
 	"git.t-juice.club/torjus/labmcp/internal/database"
 	"git.t-juice.club/torjus/labmcp/internal/nixos"
+	"git.t-juice.club/torjus/labmcp/internal/packages"
 )
 
 func TestServerInitialize(t *testing.T) {
@@ -145,6 +146,110 @@ func TestServerNotification(t *testing.T) {
 	}
 }
 
+func TestPackagesServerToolsList(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil, DefaultNixpkgsPackagesConfig())
+
+	pkgIndexer := packages.NewIndexer(store)
+	server.RegisterPackageHandlers(pkgIndexer)
+
+	input := `{"jsonrpc":"2.0","id":1,"method":"tools/list"}`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error != nil {
+		t.Fatalf("Unexpected error: %v", resp.Error)
+	}
+
+	result, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected map result, got %T", resp.Result)
+	}
+
+	tools, ok := result["tools"].([]interface{})
+	if !ok {
+		t.Fatalf("Expected tools array, got %T", result["tools"])
+	}
+
+	// Should have 6 tools (search_packages, get_package, get_file, index_revision, list_revisions, delete_revision)
+	if len(tools) != 6 {
+		t.Errorf("Expected 6 tools, got %d", len(tools))
+	}
+
+	expectedTools := map[string]bool{
+		"search_packages": false,
+		"get_package":     false,
+		"get_file":        false,
+		"index_revision":  false,
+		"list_revisions":  false,
+		"delete_revision": false,
+	}
+
+	for _, tool := range tools {
+		toolMap := tool.(map[string]interface{})
+		name := toolMap["name"].(string)
+		if _, ok := expectedTools[name]; ok {
+			expectedTools[name] = true
+		}
+	}
+
+	for name, found := range expectedTools {
+		if !found {
+			t.Errorf("Tool %q not found in tools list", name)
+		}
+	}
+}
+
+func TestOptionsServerWithPackagesToolsList(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil, DefaultNixOSConfig())
+
+	indexer := nixos.NewIndexer(store)
+	pkgIndexer := packages.NewIndexer(store)
+	server.RegisterHandlersWithPackages(indexer, pkgIndexer)
+
+	input := `{"jsonrpc":"2.0","id":1,"method":"tools/list"}`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error != nil {
+		t.Fatalf("Unexpected error: %v", resp.Error)
+	}
+
+	result, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected map result, got %T", resp.Result)
+	}
+
+	tools, ok := result["tools"].([]interface{})
+	if !ok {
+		t.Fatalf("Expected tools array, got %T", result["tools"])
+	}
+
+	// Should still have 6 tools (same as options-only)
+	if len(tools) != 6 {
+		t.Errorf("Expected 6 tools, got %d", len(tools))
+	}
+
+	// Verify index_revision is present
+	found := false
+	for _, tool := range tools {
+		toolMap := tool.(map[string]interface{})
+		if toolMap["name"].(string) == "index_revision" {
+			found = true
+			// For nixpkgs source, description should mention packages
+			desc := toolMap["description"].(string)
+			if !strings.Contains(desc, "packages") {
+				t.Errorf("index_revision description should mention packages, got: %s", desc)
+			}
+			break
+		}
+	}
+	if !found {
+		t.Error("index_revision tool not found in tools list")
+	}
+}
+
 func TestGetFilePathValidation(t *testing.T) {
 	store := setupTestStore(t)
 	server := setupTestServer(t, store)