Chameleon

Round 5 closed the malformed-argument crash class deterministically rather than by
sampling. Round 4 kept surfacing individual tools that raised on a non-string
argument (a fail-open contract violation), so instead of another agent hunt, every
model-callable tool was fuzzed exhaustively: each string parameter of all 45 tool
functions set to a list/dict/int/bool/bytes against a real repo. The sweep now
reports zero crashes.

Fixed

• merge_profiles raised on a non-string base/ours/theirs (Path() on a
  list) — guarded to a clean failed envelope.
• teach_profile raised on a non-string feedback — guarded.
• parse_edited_functions raised on a non-string file_path — guarded to its
  documented []-on-error contract.

With these, all 45 model-callable tool functions fail open (a typed envelope, never
a traceback) on any malformed string argument, verified by an exhaustive fuzz that
is now part of the confirmation battery.