Hardens test timeouts across 12 reliability and integration test files (branch-conflict recovery, merger diff/overlap guards, self-healing, worktree hydration, workflow/file-scope interactions), covering both real-git and mock-based test lanes with consistent timeout adjustments to reduce flakiness.
Fusion-Task-Id: FN-4839
Adds reliability interaction test coverage for the `no-changes-finalized` outcome (FN-4701), covering the benign case where verification-only done tasks complete with no owned commits or surviving branch.
Fusion-Task-Id: FN-4701