Add bulk fill and staggered retrofit at campus/cluster level

Campus level: "Fill All DCs" instantly fills all operational DCs with
selected SKU in one click. "Retrofit Campus" queues a staggered retrofit
with configurable concurrency (1/10%/25%/custom) so only a fraction of
DCs go offline at a time, preserving capacity during the upgrade.

Cluster level: "Fill All DCs" fills across all campuses in one action.

The game engine automatically advances the retrofit queue each tick,
promoting pending DCs as active ones complete.

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

packages/game-engine/src/systems/infrastructureSystem.ts

@@ -1,6 +1,7 @@
 import type {
   GameState, InfrastructureState, Cluster, Campus, DataCenter,
-  DeploymentCohort, NetworkHealthState, PipelineStage,
+  DeploymentCohort, NetworkHealthState, PipelineStage, RackSkuId,
+  CampusRetrofitQueue,
 } from '@ai-tycoon/shared';
 import {
   LOCATION_CONFIGS,
@@ -442,7 +443,74 @@ export function processInfrastructure(state: GameState): InfraTickResult {
         };
       });
 
-      return { ...campus, dataCenters };
+      // Process campus retrofit queue
+      let finalDCs = dataCenters;
+      let updatedQueue: CampusRetrofitQueue | null = campus.retrofitQueue ?? null;
+
+      if (updatedQueue && updatedQueue.pendingDCIds.length + updatedQueue.activeDCIds.length > 0) {
+        updatedQueue = { ...updatedQueue };
+
+        // Detect DCs that just completed retrofit (were active, now operational)
+        const newlyCompleted = finalDCs.filter(
+          dc => updatedQueue!.activeDCIds.includes(dc.id) && dc.status === 'operational',
+        );
+
+        if (newlyCompleted.length > 0) {
+          updatedQueue.activeDCIds = updatedQueue.activeDCIds.filter(
+            id => !newlyCompleted.some(dc => dc.id === id),
+          );
+          updatedQueue.completedDCIds = [
+            ...updatedQueue.completedDCIds,
+            ...newlyCompleted.map(dc => dc.id),
+          ];
+        }
+
+        // Promote DCs from pending to active
+        const slotsAvailable = updatedQueue.maxConcurrent - updatedQueue.activeDCIds.length;
+        if (slotsAvailable > 0 && updatedQueue.pendingDCIds.length > 0) {
+          const toStart = updatedQueue.pendingDCIds.slice(0, slotsAvailable);
+          updatedQueue.pendingDCIds = updatedQueue.pendingDCIds.slice(toStart.length);
+          updatedQueue.activeDCIds = [...updatedQueue.activeDCIds, ...toStart];
+
+          finalDCs = finalDCs.map(dc => {
+            if (!toStart.includes(dc.id)) return dc;
+            if (dc.status !== 'operational' || !dc.rackSkuId) return dc;
+
+            const pipelineCount = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((sum, c) => sum + c.count, 0);
+            const totalRacks = dc.computeRacksOnline + pipelineCount;
+            if (totalRacks <= 0) return dc;
+
+            const oldSku = RACK_SKU_CONFIGS[dc.rackSkuId as RackSkuId];
+            const decommTicks = Math.ceil(oldSku.pipelineTimeTicks.installation * (1 + COHORT_SCALE_FACTOR * totalRacks));
+
+            return {
+              ...dc,
+              status: 'retrofitting' as const,
+              deploymentCohorts: [],
+              retrofitState: {
+                fromSkuId: dc.rackSkuId as RackSkuId,
+                toSkuId: updatedQueue!.targetSkuId,
+                phase: 'decommissioning' as const,
+                progress: 0,
+                total: decommTicks,
+                racksRemaining: totalRacks,
+              },
+            };
+          });
+        }
+
+        // Check if queue is complete
+        if (updatedQueue.pendingDCIds.length === 0 && updatedQueue.activeDCIds.length === 0) {
+          notifications.push({
+            title: 'Campus Retrofit Complete',
+            message: `All DCs in ${campus.name} have been retrofitted to ${RACK_SKU_CONFIGS[updatedQueue.targetSkuId].name}!`,
+            type: 'success',
+          });
+          updatedQueue = null;
+        }
+      }
+
+      return { ...campus, dataCenters: finalDCs, retrofitQueue: updatedQueue };
     });
 
     return { ...cluster, campuses };

packages/shared/src/types/infrastructure.ts

@@ -18,6 +18,15 @@ export interface Cluster {
 
 export type CampusStatus = 'constructing' | 'operational';
 
+export interface CampusRetrofitQueue {
+  targetSkuId: RackSkuId;
+  maxConcurrent: number;
+  pendingDCIds: string[];
+  activeDCIds: string[];
+  completedDCIds: string[];
+  skippedDCIds: string[];
+}
+
 export interface Campus {
   id: string;
   name: string;
@@ -27,6 +36,7 @@ export interface Campus {
   status: CampusStatus;
   constructionProgress: number;
   constructionTotal: number;
+  retrofitQueue: CampusRetrofitQueue | null;
 }
 
 // --- Data Center ---