feat(part-models): detail page with fleet insights

Adds /part-models/:id mirroring host/part detail pattern: KPIs for
units, spend, avg price, failure counts, and FMs implicating the
model, a state-breakdown bar chart, and the parts-of-this-model
table. New GET /part-models/:id/insights aggregates via part.groupBy
+ aggregate and repair/fm counts.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

packages/shared/src/index.ts

@@ -18,3 +18,4 @@ export * from './webhooks.js';
 export * from './saved-views.js';
 export * from './csv-imports.js';
 export * from './analytics.js';
+export * from './part-model-insights.js';

packages/shared/src/part-model-insights.ts

@@ -0,0 +1,29 @@
+import { z } from 'zod';
+import { PartState } from './enums.js';
+
+export interface PartModelStateCount {
+  state: z.infer<typeof PartState>;
+  count: number;
+  totalPrice: number;
+}
+
+export interface PartModelPriceStats {
+  total: number;
+  average: number;
+  min: number | null;
+  max: number | null;
+  countWithPrice: number;
+}
+
+export interface PartModelFailureStats {
+  repairs: number;
+  distinctFailedParts: number;
+  fmsImplicating: number;
+}
+
+export interface PartModelInsights {
+  totalParts: number;
+  byState: PartModelStateCount[];
+  priceStats: PartModelPriceStats;
+  failures: PartModelFailureStats;
+}