Question tuning no longer pipes the question summary through printf: a
registered id needs no summary, and for an unregistered id the agent writes
the summary to .gstack/tmp/qt.txt and passes --summary-file (new). The
helper resolves a relative path against the git top level, removes scratch
files under .gstack/tmp, and asks normally when the file is missing.
/plan-tune tune events carry the user's own words again: they go into a
file the agent writes and reach gstack-question-preference --write through
--free-text-file (new), still behind the injection filter and the
user-origin gate.
docs/gbrain-write-surfaces.md drops its heredoc templates for the
agent-written page file on stdin, matching the per-skill save block, and the
generic save block stops showing a quoted --content argument.
The tuning prose was tightened so every preamble stays within its size cap.
Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>