feat(FN-4578): complete Step 1 — add milestone acceptance criteria schema

Fusion-Task-Id: FN-4578
Fusion-Task-Lineage: 1be0fa08-4d83-4988-a218-326225dfe4b5

packages/core/src/db.ts

@@ -119,7 +119,7 @@ export function probeFts5(db: DatabaseSync): boolean {
 
 // ── Schema Definition ────────────────────────────────────────────────
 
-const SCHEMA_VERSION = 79;
+const SCHEMA_VERSION = 80;
 
 function normalizeTaskComments(
   steeringComments: SteeringComment[] | undefined,
@@ -700,6 +700,7 @@ CREATE TABLE IF NOT EXISTS milestones (
   orderIndex INTEGER NOT NULL,
   interviewState TEXT NOT NULL,
   dependencies TEXT DEFAULT '[]',
+  acceptanceCriteria TEXT,
   createdAt TEXT NOT NULL,
   updatedAt TEXT NOT NULL,
   FOREIGN KEY (missionId) REFERENCES missions(id) ON DELETE CASCADE
@@ -3291,6 +3292,12 @@ export class Database {
       });
     }
 
+    if (version < 80) {
+      this.applyMigration(80, () => {
+        this.addColumnIfMissing("milestones", "acceptanceCriteria", "TEXT");
+      });
+    }
+
   }
 
   /**