feat: auto-revive in-review tasks with failed pre-merge workflow steps

Adds a SelfHealingManager scan that finds tasks parked in in-review with
a failed pre-merge workflow step and no active session, and sends them
back through the existing sendTaskBackForFix flow (PROMPT.md injection,
step reset, todo → in-progress). Bounded by a new maxPostReviewFixes
setting (default 1) and a per-task postReviewFixCount so a persistently-
failing verifier cannot ping-pong a task indefinitely.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/core/src/__tests__/task-documents.test.ts

@@ -51,7 +51,7 @@ describe("TaskStore task documents", () => {
 
     expect(tableNames.has("task_documents")).toBe(true);
     expect(tableNames.has("task_document_revisions")).toBe(true);
-    expect(db.getSchemaVersion()).toBe(37);
+    expect(db.getSchemaVersion()).toBe(38);
 
     const index = db
       .prepare(