feat(FN-5175): thread soft-delete audit context and add reconciliation scri

Adds a reconcile script to recover leaked soft-deleted tasks, threads delete audit context through all callers, and records soft-delete audit events with archive column tracking across core/engine/cli/dashboard, with reliability backstop tests covering caller alignment.

Fusion-Task-Id: FN-5175

scripts/__tests__/reconcile-leaked-soft-deletes.test.mjs

@@ -0,0 +1,119 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { DatabaseSync } from "node:sqlite";
+
+import { reconcileLeakedSoftDeletes } from "../reconcile-leaked-soft-deletes.mjs";
+
+function setupFixture() {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "fn-5175-"));
+  const dbPath = path.join(dir, "fusion.db");
+  const db = new DatabaseSync(dbPath);
+
+  db.exec(`
+    CREATE TABLE tasks (
+      id TEXT PRIMARY KEY,
+      "column" TEXT NOT NULL,
+      status TEXT,
+      deletedAt TEXT,
+      updatedAt TEXT
+    );
+
+    CREATE TABLE runAuditEvents (
+      id TEXT PRIMARY KEY,
+      timestamp TEXT NOT NULL,
+      taskId TEXT,
+      agentId TEXT NOT NULL,
+      runId TEXT NOT NULL,
+      domain TEXT NOT NULL,
+      mutationType TEXT NOT NULL,
+      target TEXT NOT NULL,
+      metadata TEXT
+    );
+  `);
+
+  return { dir, db };
+}
+
+function insertTask(db, row) {
+  db.prepare(`INSERT INTO tasks (id, "column", status, deletedAt, updatedAt) VALUES (?, ?, ?, ?, ?)`)
+    .run(row.id, row.column, row.status ?? null, row.deletedAt ?? null, row.updatedAt ?? null);
+}
+
+test("reconciles leaked soft-deletes and is idempotent on re-run", () => {
+  const { dir, db } = setupFixture();
+  try {
+    insertTask(db, {
+      id: "FN-5130",
+      column: "in-review",
+      status: "failed",
+      deletedAt: "2026-05-19T00:00:00.000Z",
+      updatedAt: "2026-05-19T00:00:00.000Z",
+    });
+    insertTask(db, {
+      id: "FN-5133",
+      column: "todo",
+      status: null,
+      deletedAt: "2026-05-19T01:00:00.000Z",
+      updatedAt: "2026-05-19T01:00:00.000Z",
+    });
+    insertTask(db, {
+      id: "FN-5167",
+      column: "archived",
+      status: null,
+      deletedAt: "2026-05-19T02:00:00.000Z",
+      updatedAt: "2026-05-19T02:00:00.000Z",
+    });
+
+    const result = reconcileLeakedSoftDeletes({
+      db,
+      dryRun: false,
+      runId: "synthetic-reconcile-fn-5175-test",
+    });
+
+    assert.equal(result.rowsScanned, 2);
+    assert.equal(result.rowsUpdated, 2);
+    assert.equal(result.auditRowsInserted, 2);
+
+    const columns = db.prepare(`SELECT id, "column" FROM tasks ORDER BY id`).all().map((row) => ({ ...row }));
+    assert.deepEqual(columns, [
+      { id: "FN-5130", column: "archived" },
+      { id: "FN-5133", column: "archived" },
+      { id: "FN-5167", column: "archived" },
+    ]);
+
+    const audits = db.prepare(`SELECT taskId, agentId, runId, mutationType, target, metadata FROM runAuditEvents ORDER BY taskId`).all().map((row) => ({ ...row }));
+    assert.equal(audits.length, 2);
+    assert.deepEqual(audits.map((row) => row.taskId), ["FN-5130", "FN-5133"]);
+    assert.ok(audits.every((row) => row.agentId === "system"));
+    assert.ok(audits.every((row) => row.runId === "synthetic-reconcile-fn-5175-test"));
+    assert.ok(audits.every((row) => row.mutationType === "task:soft-delete-column-reconcile"));
+    assert.deepEqual(audits.map((row) => JSON.parse(row.metadata)), [
+      {
+        previousColumn: "in-review",
+        previousStatus: "failed",
+        source: "FN-5175 reconcile",
+      },
+      {
+        previousColumn: "todo",
+        previousStatus: null,
+        source: "FN-5175 reconcile",
+      },
+    ]);
+
+    const second = reconcileLeakedSoftDeletes({
+      db,
+      dryRun: false,
+      runId: "synthetic-reconcile-fn-5175-test-2",
+    });
+    assert.equal(second.rowsScanned, 0);
+    assert.equal(second.rowsUpdated, 0);
+    assert.equal(second.auditRowsInserted, 0);
+    assert.equal(db.prepare("SELECT COUNT(*) AS count FROM runAuditEvents").get().count, 2);
+  } finally {
+    db.close();
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+});