fix: guard against unknown epic IDs inflating progress above 100%

Unknown/legacy epic IDs persisted in state but absent from EPIC_CONFIG
would pass the `!EPIC_CONFIG[num]?.onDemand` filter (since
`undefined?.onDemand` is `undefined`, and `!undefined` is `true`),
inflating completedEpics count above the totalEpics denominator.

Add `EPIC_CONFIG[num] &&` guard in both `getProgressPercentage()` and
`_calculateProgressFromState()` so only known epics are counted.

Author: nikolasdehor

.aiox-core/core/orchestration/master-orchestrator.js

@@ -1358,7 +1358,7 @@ class MasterOrchestrator extends EventEmitter {
     if (totalEpics === 0) return 0;
 
     const completedEpics = Object.entries(state.epics).filter(
-      ([num, epic]) => epic.status === EpicStatus.COMPLETED && !EPIC_CONFIG[num]?.onDemand,
+      ([num, epic]) => epic.status === EpicStatus.COMPLETED && EPIC_CONFIG[num] && !EPIC_CONFIG[num].onDemand,
     ).length;
 
     return Math.round((completedEpics / totalEpics) * 100);
@@ -1415,7 +1415,7 @@ class MasterOrchestrator extends EventEmitter {
     if (totalEpics === 0) return 0;
 
     const completedEpics = Object.entries(this.executionState.epics).filter(
-      ([num, epic]) => epic.status === EpicStatus.COMPLETED && !EPIC_CONFIG[num]?.onDemand,
+      ([num, epic]) => epic.status === EpicStatus.COMPLETED && EPIC_CONFIG[num] && !EPIC_CONFIG[num].onDemand,
     ).length;
 
     return Math.round((completedEpics / totalEpics) * 100);