Sistema de códigos jerárquicos 2-niveles + asignación determinista post-IA

- hierarchy.ts: Spike (S) agregado, buildHierarchyPath genera [E01-F04] (2 niveles)
  Legacy [E05-F04-U01] preservado (regex opcional 3er segmento)
- hierarchy-generator.ts (nuevo): analyzeExisting() computa contadores por épica+tipo
  assignEpicCodes() asigna E{max+1} secuencial
  assignItemCodes() asigna {epic}-{tipo}{n+1} a cada HU dentro de su épica
- project-analyzer.ts: post-procesa épicas y HUs con generador de códigos
  saveEpicDrafts usa epicCode en metadata y título con [E01]
- prompts-db.ts: prompt FASE 2 instruye a la IA a no generar códigos
- workitems.ts: EnrichedEpic._epicCode, EnrichedUserStory._epicCode/_itemCode
- DashboardView: muestra códigos en drafts y tabla de épicas

src/stores/workitems.ts

@@ -19,12 +19,15 @@ export interface EnrichedUserStory extends KappaUserStory {
   _assignedName: string
   _statusName: string
   _assignedEmployeeId: number | null
+  _epicCode: string | null
+  _itemCode: string | null
 }
 
 export interface EnrichedEpic extends KappaEpicDevelopment {
   _itemType: ItemType
   _hierarchyPath: string | null
   _cleanName: string
+  _epicCode: string | null
 }
 
 export const useWorkItemsStore = defineStore('workitems', () => {
@@ -61,6 +64,7 @@ export const useWorkItemsStore = defineStore('workitems', () => {
       _itemType: h?.items[h.items.length - 1]?.type || 'E',
       _hierarchyPath: h?.fullPath ?? null,
       _cleanName: h ? stripHierarchy(title) : title,
+      _epicCode: h?.epicCode ?? null,
     }
   }
 
@@ -113,6 +117,8 @@ export const useWorkItemsStore = defineStore('workitems', () => {
       _assignedName: assignedName,
       _statusName: hu.status_name || resolveStatusName(hu.status),
       _assignedEmployeeId: employeeId,
+      _epicCode: h?.epicCode ?? null,
+      _itemCode: h?.itemCode ?? null,
     }
   }