Add Stash to Session managers & parallel runners

[SectorOPS]

Adds Stash to Session managers & parallel runners.

• Repo: https://github.com/SectorOPS/Stash
• License: MIT
• One-line pitch: an interactive launcher that walks claude/codex/opencode session storage, groups by project directory, and resumes the right session with the right --resume <uuid> in a new terminal — across all three tools from one picker.

Why it's distinct from the existing entries in this section: most of them orchestrate multiple parallel sessions; Stash is focused on finding the right past session (fuzzy search across all three tools, live preview pane of the last user + assistant turns, per-tool format validation via stash doctor).

Meets the inclusion rules:

• CLI / terminal interface ✓
• Autonomously runs commands (via the agents it launches) ✓
• Active repo with releases ✓