feat(mcp): 16 PM tools + chat tool + 6 resource URIs + admin token UI

Phase F: tools_pm.go — list/get/create/update/close/reopen/assign for
projects, workspaces, requirements, issues (16 tools total).

Phase G: tools_chat.go — list_recent_messages tool; resources.go — 6 PM
resource URI templates (projects, project-detail, requirements, issues,
workspaces, workspace-detail).

Phase H: frontend admin UI — mcpTokens API client, Pinia store,
MCPTokenAdminView with create/revoke/list, router entry, NavBar link.

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

internal/mcp/server.go

@@ -37,7 +37,6 @@ func NewMCPServer(deps ServerDeps) *mcpsdk.Server {
 	return srv
 }
 
-// register* 占位函数在后续 Phase F/G 实装时替换函数体。
-func registerPMTools(_ *mcpsdk.Server, _ ServerDeps)    {}
-func registerChatTools(_ *mcpsdk.Server, _ ServerDeps)  {}
-func registerResources(_ *mcpsdk.Server, _ ServerDeps)  {}
+// registerChatTools 已在 tools_chat.go 中实现。
+// registerResources 已在 resources.go 中实现。
+// registerPMTools 已在 tools_pm.go 中实现。