feat(FN-3937): document architecture recovery layers and lifecycle alignmen

Added documentation for Fusion's architecture recovery layers (deadlock self-healing, paused-aware in-review filtering) and aligned lifecycle docs, with a new test validating that the self-healing docs stay in sync with the source code.

Fusion-Task-Id: FN-3937

scripts/__tests__/self-healing-docs.test.mjs

@@ -0,0 +1,38 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+const architecturePath = path.resolve(__dirname, "../../docs/architecture.md");
+const taskManagementPath = path.resolve(__dirname, "../../docs/task-management.md");
+const architectureDoc = readFileSync(architecturePath, "utf8");
+const taskManagementDoc = readFileSync(taskManagementPath, "utf8");
+
+test("architecture self-healing section documents already-merged review recovery layer", () => {
+  assert.ok(
+    architectureDoc.includes("recoverAlreadyMergedReviewTasks()"),
+    "Expected docs/architecture.md to mention recoverAlreadyMergedReviewTasks()",
+  );
+
+  assert.ok(
+    architectureDoc.includes("Together, `recoverAlreadyMergedReviewTasks()`, `clearStaleBlockedBy()`, and paused-aware in-review scheduling"),
+    "Expected architecture docs to describe the layered merge-deadlock self-healing defenses",
+  );
+});
+
+test("task lifecycle docs describe preserved failed review state plus already-landed auto-finalization", () => {
+  assert.ok(
+    taskManagementDoc.includes("This state is intentionally preserved by recovery (not auto-bounced to `todo`)."),
+    "Expected task-management docs to preserve failed in-review tasks",
+  );
+
+  assert.match(
+    taskManagementDoc,
+    /Self-healing can still auto-finalize retry-exhausted failed review tasks[\s\S]*already landed on the merge target/,
+    "Expected task-management docs to explain already-landed failed-review auto-finalization",
+  );
+});