What does this PR do?

_list_recent_sessions() in session_search_tool.py blanket-skips all sessions with parent_session_id set (line 292: if s.get("parent_session_id"): continue). This correctly hides delegation child sessions, but also hides compression-continuation sessions — sessions created when context compression splits a long conversation into a parent (archived) and child (active continuation). Users who compress long conversations lose all access to the continuation via session search, creating a "memory black hole".

Related Issue

Fixes #13840

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• tools/session_search_tool.py: Change the blanket parent_session_id filter to also check end_reason. Compression-continuation sessions (which have end_reason == "compression") are now visible, while delegation children remain hidden.

How to Test

1. Run the targeted test:

   python -m pytest tests/tools/test_session_search_compression.py -v

2. The 3 tests cover:
   • Compression-continuation sessions (parent + end_reason=compression) are visible
   • Delegation child sessions (parent, no compression reason) stay hidden
   • Root sessions without parent remain visible

Tested on macOS (Python 3.14).

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS 15 (Darwin 24.6.0)

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Screenshots / Logs

python -m pytest tests/tools/test_session_search_compression.py -v
# 3 passed