feat(dashboard): real business metrics with week-over-week trends

Dashboard KPIs were three flat counters with no trend data — the cards
rendered a neutral dash where the design intends movement indicators.
Summary now queries three trailing windows and emits four KPIs with
real deltas: bookings this week, completed (new CompletedCount metric
in both repositories), cancellations, and utilization in percentage
points. KPI labels localize in the frontend via a code-to-key map so
Czech operators no longer see English labels on live data.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

packages/api-client/src/generated/types.ts

@@ -1101,8 +1101,11 @@ export interface components {
             startsAt: string;
         };
         DashboardKPI: {
+            change?: string;
             code: string;
             label: string;
+            /** @enum {string} */
+            trend?: "up" | "down" | "neutral";
             value: string;
         };
         DashboardSummary: {