feat(FN-1569): add mission validation telemetry APIs and UI

- Emit fix-feature mission events and forward validator telemetry through mission execution
- Add core and dashboard API types plus a validation telemetry route in mission-routes
- Update SSE mission event handling so validation telemetry updates stream reliably to clients
- Add telemetry surfaces in MissionManager with corresponding mission-specific UI styling
- Expand MissionManager and mission e2e test coverage for validation telemetry flows

packages/core/src/index.ts

@@ -276,6 +276,7 @@ export type {
   FeatureEventPayload,
   FeatureDeletedPayload,
   FeatureLinkedPayload,
+  FixFeatureCreatedPayload,
   // Validator run types
   MissionValidatorRun,
   MissionAssertionFailureRecord,

packages/core/src/mission-store.ts

@@ -40,6 +40,7 @@ import type {
   SlicePlanState,
   MissionContractAssertion,
   FeatureAssertionLink,
+  FixFeatureCreatedPayload,
   MilestoneValidationRollup,
   ContractAssertionCreateInput,
   ContractAssertionUpdateInput,
@@ -122,6 +123,8 @@ export interface MissionStoreEvents {
   "validator-run:started": [MissionValidatorRun];
   /** Emitted when a validator run is completed (run, final status, durationMs) */
   "validator-run:completed": [MissionValidatorRun, ValidatorRunStatus, number];
+  /** Emitted when a generated fix feature is created after failed validation */
+  "fix-feature:created": [FixFeatureCreatedPayload];
 }
 
 // ── MissionStore Class ──────────────────────────────────────────────
@@ -2177,6 +2180,12 @@ export class MissionStore extends EventEmitter<MissionStoreEvents> {
 
     this.db.bumpLastModified();
     this.emit("feature:created", fixFeature);
+    this.emit("fix-feature:created", {
+      feature: fixFeature,
+      sourceFeatureId,
+      runId,
+      failedAssertionIds,
+    });
 
     return fixFeature;
   }

packages/core/src/mission-types.ts

@@ -484,6 +484,18 @@ export interface FeatureLinkedPayload {
   taskId: string;
 }
 
+/** Payload for fix-feature:created event */
+export interface FixFeatureCreatedPayload {
+  /** The generated fix feature */
+  feature: MissionFeature;
+  /** Source feature ID that failed validation */
+  sourceFeatureId: string;
+  /** Validator run ID that triggered the fix generation */
+  runId: string;
+  /** Assertion IDs that failed and triggered the fix */
+  failedAssertionIds: string[];
+}
+
 // ── Contract Assertion Types ────────────────────────────────────────
 
 /**