fix: TS2322 in CalendarPage — typed bootstrap result vars outside JSX

Record<string, T> index type prevents 'error' in narrowing, causing
string | T to leak into ReactNode positions. Fix: precompute
bootstrapError (string|null) and bootstrapEntries ([string, T][])
before JSX so TypeScript can resolve types correctly.

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

frontend/src/pages/CalendarPage.tsx

@@ -41,9 +41,16 @@ interface SeriesMeta {
   assets: string[]
 }
 
+interface BootstrapSeriesResult {
+  status: string
+  name?: string
+  inserted?: number
+  skipped?: number
+}
+
 interface BootstrapStatus {
   running: boolean
-  last_result: Record<string, { status: string; inserted: number; skipped: number }> | { error: string } | null
+  last_result: unknown
 }
 
 // ── Constants ─────────────────────────────────────────────────────────────────
@@ -152,8 +159,15 @@ function BootstrapPanel({ onDone }: { onDone: () => void }) {
     return () => clearInterval(iv)
   }, [polling])
 
-  const result = bsStatus.last_result
-  const hasError = result && 'error' in result
+  const rawResult = bsStatus.last_result as Record<string, unknown> | null
+  const bootstrapError: string | null =
+    rawResult && typeof (rawResult as { error?: unknown }).error === 'string'
+      ? (rawResult as { error: string }).error
+      : null
+  const bootstrapEntries: [string, BootstrapSeriesResult][] =
+    rawResult && !bootstrapError
+      ? (Object.entries(rawResult) as [string, BootstrapSeriesResult][])
+      : []
 
   return (
     <div className="card border-blue-500/30 p-4 space-y-3">
@@ -197,19 +211,19 @@ function BootstrapPanel({ onDone }: { onDone: () => void }) {
         </div>
       )}
 
-      {result && !bsStatus.running && (
-        hasError ? (
-          <div className="text-xs text-red-400">Erreur : {'error' in result ? result.error : ''}</div>
+      {rawResult && !bsStatus.running && (
+        bootstrapError ? (
+          <div className="text-xs text-red-400">Erreur : {bootstrapError}</div>
         ) : (
           <div className="grid grid-cols-3 gap-2 mt-2">
-            {Object.entries(result as Record<string, { status: string; inserted: number; skipped: number; name: string }>).map(([sid, r]) => (
+            {bootstrapEntries.map(([sid, r]) => (
               <div key={sid} className={clsx(
                 'text-xs px-2 py-1 rounded border',
                 r.status === 'ok' ? 'border-emerald-700/30 bg-emerald-900/5 text-emerald-300'
                   : 'border-red-700/30 text-red-400',
               )}>
                 <span className="font-mono text-slate-400">{sid}</span>{' '}
-                {r.status === 'ok' ? `+${r.inserted} / skip ${r.skipped}` : 'failed'}
+                {r.status === 'ok' ? `+${r.inserted ?? 0} / skip ${r.skipped ?? 0}` : 'failed'}
               </div>
             ))}
           </div>