Tighten ToolRuntime._enforce_capabilities() to block ANY tool with
writes=True when plan_read_only is set, removing the not-cap.read_only
loophole that allowed certain write tools through. Tool name is now
always included in the ToolAccessDeniedError message.
Add read_only flag to ChangeSetCapture with ReadOnlyViolationError
raised when write-capable tools are wrapped on a read-only plan.
Add CLI fail-fast guards on plan execute and plan apply commands that
abort before calling the service layer if plan.read_only is True.
SkillContext.enforce_write_guard() already included tool name
correctly and required no changes.
Includes 18 Behave scenarios (90 steps), Robot integration tests,
ASV benchmarks, and docs/reference/read_only_actions.md.
ISSUES CLOSED: #322
khyari hamza