feat(ui): synthesis/superseded badges + merge provenance in lessons-tab (#162)

עוצב ואושר דרך שער-העיצוב (Claude Design 12c-training-lessons.html).
- lessons-tab: SOURCE_BADGE['synthesis']="סינתזה" (navy מלא) · REVIEW_BADGE['superseded']="מוזג"
  (אפור-מעומעם, לא נדחה); שורות superseded מעומעמות (opacity).
- provenance: לקח-על מציג "⤷ מוזג מ-N לקחים · דחייה תשחזר אותם".
- backend: list_decision_lessons + _lesson_to_json מחזירים synthesized_from; training.ts
  DecisionLesson — 'synthesis'/'superseded' ל-unions + synthesized_from?: string[].

הבאדג'ים היו מוגנים-fallback קודם (ללא קריסה) — כעת מתויגים נכון. closes #162.

בדיקות: py_compile ✓ · leak-guard ✓ · tsc --noEmit ✓.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-ui/src/components/training/lessons-tab.tsx

@@ -54,6 +54,9 @@ const SOURCE_BADGE: Record<string, { label: string; cls: string }> = {
   curator: { label: "הרמס (סקירה)", cls: "bg-info-bg text-info" },
   style_analyzer: { label: "מנתח-סגנון", cls: "bg-success-bg text-success" },
   "panel:deepseek+gemini": { label: "פאנל: דיפסיק+גמיני", cls: "bg-gold-wash text-gold-deep" },
+  // #158/INV-LRN8 — a super-lesson merging overlapping lessons; navy-filled so it
+  // reads as the consolidated/elevated one.
+  synthesis: { label: "סינתזה", cls: "bg-navy text-parchment" },
 };
 
 const SOURCE_BADGE_FALLBACK = { label: "פאנל", cls: "bg-rule-soft text-ink-soft" };
@@ -63,6 +66,9 @@ const REVIEW_BADGE: Record<string, { label: string; cls: string }> = {
   proposed: { label: "ממתין לאישור", cls: "bg-gold-wash text-gold-deep border-gold/40" },
   approved: { label: "מאושר · זורם לכותב", cls: "bg-success-bg text-success border-success/40" },
   rejected: { label: "נדחה", cls: "bg-rule-soft text-ink-muted line-through" },
+  // #158/INV-LRN8 — merged into a synthesis super-lesson; kept as provenance, no
+  // longer fed to the writer. Muted (not struck — it wasn't rejected).
+  superseded: { label: "מוזג", cls: "bg-rule-soft text-ink-muted" },
 };
 
 export function LessonsTab({ corpusId }: { corpusId: string }) {
@@ -201,8 +207,10 @@ function LessonItem({
     }
   };
 
+  const mergedCount = lesson.source === "synthesis" ? (lesson.synthesized_from?.length ?? 0) : 0;
+
   return (
-    <Card className="bg-surface border-rule">
+    <Card className={`bg-surface border-rule ${lesson.review_status === "superseded" ? "opacity-70" : ""}`}>
       <CardContent className="px-4 py-3 space-y-2">
         <div className="flex items-center gap-2 text-[0.72rem]">
           <Badge variant="outline"
@@ -220,6 +228,12 @@ function LessonItem({
           </span>
         </div>
 
+        {mergedCount > 0 && (
+          <div className="text-[0.72rem] text-ink-muted">
+            ⤷ מוזג מ-<b className="text-navy font-semibold">{mergedCount} לקחים</b> · דחייה תשחזר אותם
+          </div>
+        )}
+
         {editing ? (
           <>
             <Textarea value={text} onChange={(e) => setText(e.target.value)}