fix: preserve persona and language continuity in compaction summaries (#10456)

Merged via squash.

Prepared head SHA: 4518fb20e1
Co-authored-by: keepitmello <71975659+keepitmello@users.noreply.github.com>
Co-authored-by: jalehman <550978+jalehman@users.noreply.github.com>
Reviewed-by: @jalehman

CHANGELOG.md

@@ -3,6 +3,7 @@
 Docs: https://docs.openclaw.ai
 
 ## Unreleased
+
 ### Changes
 
 - Android/chat settings: redesign the chat settings sheet with grouped device and media sections, refresh the Connect and Voice tabs, and tighten the chat composer/session header for a denser mobile layout. (#44894) Thanks @obviyus.
@@ -28,6 +29,8 @@ Docs: https://docs.openclaw.ai
 - Security/exec approvals: fail closed for Perl `-M` and `-I` approval flows so preload and load-path module resolution stays outside approval-backed runtime execution unless the operator uses a broader explicit trust path.
 - Control UI/insecure auth: preserve explicit shared token and password auth on plain-HTTP Control UI connects so LAN and reverse-proxy sessions no longer drop shared auth before the first WebSocket handshake. (#45088) Thanks @velvet-shark.
 - macOS/onboarding: avoid self-restarting freshly bootstrapped launchd gateways and give new daemon installs longer to become healthy, so `openclaw onboard --install-daemon` no longer false-fails on slower Macs and fresh VM snapshots.
+- Agents/compaction: preserve safeguard compaction summary language continuity via default and configurable custom instructions so persona drift is reduced after auto-compaction. (#10456) Thanks @keepitmello.
+
 ## 2026.3.12
 
 ### Changes