unbounded shell tool output blows the agent's context window on commands
that dump big logs (test runners, build tools, grep on large trees). cap
the inline body at 5000 chars; on overflow, persist the full output to
${PULLFROG_TEMP_DIR}/shell-<id>.log and return the tail prefixed with a
sentinel pointing at the saved path. agents re-read the tempfile with
cat/tail/grep when they need more.
Colin McDonnell
2960d51493