feat(PBI-59): Sprint.code (SP-N sequentieel per product) (#153)

Voegt een verplicht code-veld toe aan Sprint, sequentieel per product
(consistent met PBI-N, ST-NNN, T-N).

- **Schema** — `Sprint.code String @db.VarChar(30)` + `@@unique([product_id, code])`
- **Migratie** — voegt kolom toe als nullable, backfillt bestaande sprints
  via `ROW_NUMBER() OVER (PARTITION BY product_id ORDER BY created_at)`
  als `SP-N`, en zet daarna NOT NULL + UNIQUE.
- **Generator** — `generateNextSprintCode(productId)` in lib/code-server.ts
  volgt het patroon van story/pbi/task; createSprintAction gebruikt
  `createWithCodeRetry` voor race-bescherming.
- **Seed** — sprint-counter per product (`SP-1`, `SP-2`, ...).

Zichtbaar in:
- Sprint-header (`Product › Sprint actief · SP-3`)
- JobCard + JobDetailPane voor SPRINT_IMPLEMENTATION jobs
- Insights: VelocityChart x-axis (compacter dan goal-truncated),
  AlignmentTrend tooltip, SprintInfoStrip
- actions/jobs-page.ts: `sprintCode` is weer een echte code i.p.v. null

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

app/(app)/insights/components/alignment-trend.tsx

@@ -15,7 +15,7 @@ interface Props {
 }
 
 interface TooltipPayload {
-  payload?: { total: number; alignedRatio: number; sprintGoal: string }
+  payload?: { total: number; alignedRatio: number; sprintCode: string; sprintGoal: string }
 }
 
 function CustomTooltip({ active, payload }: { active?: boolean; payload?: TooltipPayload[] }) {
@@ -25,7 +25,10 @@ function CustomTooltip({ active, payload }: { active?: boolean; payload?: Toolti
   const aligned = Math.round((d.alignedRatio / 100) * d.total)
   return (
     <div className="rounded border border-border bg-surface-container px-3 py-2 text-sm shadow">
-      <p className="font-medium text-foreground">{d.sprintGoal}</p>
+      <p className="font-medium text-foreground">
+        <span className="font-mono text-xs text-muted-foreground mr-2">{d.sprintCode}</span>
+        {d.sprintGoal}
+      </p>
       <p className="text-muted-foreground">
         {aligned} / {d.total} aligned ({d.alignedRatio}%)
       </p>
@@ -33,10 +36,6 @@ function CustomTooltip({ active, payload }: { active?: boolean; payload?: Toolti
   )
 }
 
-function sprintLabel(goal: string): string {
-  return goal.length > 20 ? goal.slice(0, 18) + '…' : goal
-}
-
 export function AlignmentTrend({ trend }: Props) {
   if (trend.length === 0) {
     return (
@@ -48,7 +47,7 @@ export function AlignmentTrend({ trend }: Props) {
 
   const data = trend.map(p => ({
     ...p,
-    label: sprintLabel(p.sprintGoal),
+    label: p.sprintCode,
   }))
 
   return (

app/(app)/insights/components/sprint-info-strip.tsx

@@ -2,6 +2,7 @@
 
 interface SprintInfo {
   sprintId: string
+  sprintCode: string
   productName: string
   sprintGoal: string
   taskCount: number
@@ -33,6 +34,7 @@ export function SprintInfoStrip({ sprints }: Props) {
           className="flex items-center gap-3 rounded-lg border border-border bg-surface-container px-3 py-2 text-sm"
         >
           <span className="font-medium text-foreground">{s.productName}</span>
+          <span className="font-mono text-xs text-muted-foreground">{s.sprintCode}</span>
           <span className="text-muted-foreground">{truncate(s.sprintGoal, 60)}</span>
           <span className={`font-mono tabular-nums ${daysLeftColor(s.daysLeft)}`}>
             {s.daysLeft > 0 ? `${s.daysLeft}d over` : `${Math.abs(s.daysLeft)}d over tijd`}

app/(app)/insights/components/velocity-chart.tsx

@@ -35,11 +35,9 @@ export function VelocityChart({ data }: Props) {
   type Row = { sprintLabel: string } & Record<string, number | string>
   const grouped = new Map<string, Row>()
   for (const s of sprints) {
-    const label =
-      s.sprintGoal.length > 14 ? s.sprintGoal.slice(0, 14) + '…' : s.sprintGoal
     const key = `${s.sprintId}`
     if (!grouped.has(key)) {
-      grouped.set(key, { sprintLabel: label })
+      grouped.set(key, { sprintLabel: s.sprintCode })
     }
     grouped.get(key)![s.productName] = s.doneCount
   }

app/(app)/insights/page.tsx

@@ -60,6 +60,7 @@ export default async function InsightsPage({ searchParams }: InsightsPageProps)
       where: { status: 'ACTIVE', product: productAccessFilter(userId) },
       select: {
         id: true,
+        code: true,
         sprint_goal: true,
         created_at: true,
         product: { select: { id: true, name: true } },
@@ -88,6 +89,7 @@ export default async function InsightsPage({ searchParams }: InsightsPageProps)
   const nowMs = Date.now()
   const sprintInfos = activeSprints.map(s => ({
     sprintId: s.id,
+    sprintCode: s.code,
     productId: s.product.id,
     productName: s.product.name,
     sprintGoal: s.sprint_goal,

app/(app)/products/[id]/sprint/page.tsx

@@ -38,6 +38,7 @@ export default async function SprintBoardPage({ params, searchParams }: Props) {
     where: { product_id: id, status: { in: ['ACTIVE', 'FAILED'] } },
     select: {
       id: true,
+      code: true,
       sprint_goal: true,
       status: true,
       start_date: true,