fix: package context compaction module

[EvanProgramming]

Summary

• include context_compaction.py in the installed wheel
• keep the distribution regression test aligned with runtime imports
• update the installed-wheel acceptance hook to the renamed summarizer

Root cause

history.py imports context_compaction, but setuptools omitted that module from py-modules. Both kyrozen and kyrozen-backend therefore exited during import, and the TUI surfaced only backend exited: exit status 1.

Verification

• real installed kyrozen reached READY with the existing user configuration
• isolated installed backend emitted ready and exited cleanly
• wheel smoke passed from an unrelated directory
• 271 Python tests passed
• make check passed
• make lint passed
• focused distribution and agent acceptance checks passed

No web UI or backend protocol contract changed.