Scopes lane-gc.sh down to the two pieces that match CCAM's actual
architecture (orphan Playwright MCP reap, oversized-log capping).
Drops auto-removing stale worktrees by age — that's exactly the kind
of automatic destructive action this repo's own CLAUDE.md forbids
(destroy always goes through the three-check guard, never automatic).
State archiving and scratch-debris sweep don't apply either (different
storage architecture; CCAM doesn't generate those files).
