feat(ST-1275): render SKIPPED job status in chart-colors and insights

Closing the gap left when ClaudeJobStatus.SKIPPED was added to the schema:
the badge map and case-mapper already covered it, but the chart palette,
the per-day insights aggregator and the stacked-bar chart did not. SKIPPED
jobs (e.g. cmovkur8 manually flipped during the no-op-exit hotfix) now
render with a muted style consistent with cancelled.

- lib/chart-colors.ts: JOB_STATUS_COLORS gains a 'skipped' entry
  (var(--muted-foreground), same intensity as cancelled — neither rood/orange)
- lib/insights/agent-throughput.ts: DayCount + STATUSES + perDay zero-fill
  now include 'skipped'; the SQL terminal_7d filter already counted SKIPPED
- app/(app)/insights/components/agent-throughput.tsx: STACKED_STATUSES and
  the empty-state guard include 'skipped'
- __tests__: chart-colors keys list, job-status round-trip ('all 7 statuses')
  and the insights non-zero filter all account for SKIPPED

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/chart-colors.ts

@@ -28,6 +28,7 @@ export const JOB_STATUS_COLORS = {
   done: 'var(--status-done)',
   failed: 'var(--priority-critical)',
   cancelled: 'var(--muted-foreground)',
+  skipped: 'var(--muted-foreground)',
 } as const
 
 export const SERIES_COLORS = [

lib/insights/agent-throughput.ts

@@ -8,6 +8,7 @@ export interface DayCount {
   done: number
   failed: number
   cancelled: number
+  skipped: number
 }
 
 export interface ThroughputKpi {
@@ -21,7 +22,7 @@ export interface JobsPerDayResult {
   kpi: ThroughputKpi
 }
 
-const STATUSES = ['queued', 'claimed', 'running', 'done', 'failed', 'cancelled'] as const
+const STATUSES = ['queued', 'claimed', 'running', 'done', 'failed', 'cancelled', 'skipped'] as const
 
 type RawDayRow = { day: Date; status: string; count: bigint }
 type RawKpiRow = { today_count: bigint; done_7d: bigint; terminal_7d: bigint; avg_seconds: number | null }
@@ -100,6 +101,7 @@ export async function getJobsPerDay(
       done: statusMap.get('done') ?? 0,
       failed: statusMap.get('failed') ?? 0,
       cancelled: statusMap.get('cancelled') ?? 0,
+      skipped: statusMap.get('skipped') ?? 0,
     })
   }