feat: timeline multi-select, demand popover, resource hover card, merged tooltips, dark mode fixes

Major timeline enhancements:
- Right-click drag multi-selection with floating action bar (batch delete/assign)
- DemandPopover for demand strip details (replaces broken "Loading" modal)
- ResourceHoverCard on name hover showing skills, rates, role, chapter
- Merged heatmap+vacation tooltips into unified TimelineTooltip component
- Fixed overbooking blink animation (date normalization, z-index ordering)
- Fixed dark mode sticky column bleed-through in project view
- System roles admin page, notification task management, performance review docs

Co-Authored-By: claude-flow <ruv@ruv.net>

packages/api/src/router/index.ts

@@ -22,6 +22,7 @@ import { resourceRouter } from "./resource.js";
 import { roleRouter } from "./role.js";
 import { settingsRouter } from "./settings.js";
 import { staffingRouter } from "./staffing.js";
+import { systemRoleConfigRouter } from "./system-role-config.js";
 import { timelineRouter } from "./timeline.js";
 import { userRouter } from "./user.js";
 import { utilizationCategoryRouter } from "./utilization-category.js";
@@ -55,6 +56,7 @@ export const appRouter = createTRPCRouter({
   chargeabilityReport: chargeabilityReportRouter,
   calculationRule: calculationRuleRouter,
   computationGraph: computationGraphRouter,
+  systemRoleConfig: systemRoleConfigRouter,
 });
 
 export type AppRouter = typeof appRouter;