FN-6198: unquarantine self-healing db corruption test

Restore the self-healing DB corruption test to the default engine suite.

- remove the engine vitest exclude for self-healing-db-corruption.test.ts
- clear the quarantine ledger entry for the restored test

Files changed:
 packages/engine/vitest.config.ts | 1 -
 scripts/lib/test-quarantine.json | 8 +-------
 2 files changed, 1 insertion(+), 8 deletions(-)

Fusion-Task-Id: FN-6198

Fusion-Task-Lineage: 2466b040-956d-4138-89d5-137d1721081c

packages/engine/vitest.config.ts

@@ -95,7 +95,6 @@ export default defineConfig({
           include: ["src/**/*.test.ts"],
           exclude: [
             "src/__tests__/reliability-interactions/**/*.test.ts",
-            "src/__tests__/self-healing-db-corruption.test.ts",
             // Real-git heavy files run in the engine-slow project so local
             // `pnpm test` stays snappy. CI picks them up via `test:slow`
             // / `test:all` invoked from the root `test:full` script.