#28238 fix(inspector): hide unsupported chat environment save

Active chat panes were wiring the Session Info Environment Save button to environment.save, but the native handler only accepts that operation from New Tab. Every real chat click therefore failed and the retry could never succeed. The App now leaves that optional callback unset for active chats; gallery and other host integrations can still supply it.

Validation: focused browser tests for Session Info and environment save.

Risk: removes an action that was always rejected in active chats; supported New Tab integrations retain their own callback.

Agent session: agent session