Three audited collisions where a crashed inspector fallback could persist
over new healthy content: review keyed on section id only (ids recur across
threads/worktrees), files used threadId ?? cwd (a worktree move under a
stable thread id left the key unchanged), and the thread screen's
workspace-bound Files/Git modes keyed on thread + mode without the cwd
they actually render. One builder — source, workspace key, cwd, content
selection — replaces both helpers; tests cover failed-fallback -> healthy
content switching for each registrant path.