v0.31.2 — make-skill

• FW01 expands the Python temporary-tree source check to the owning repository,
  with the documented excluded directories and lexical limits preserved.
• Only the exact ledger path, allocation count and call shape receive the existing
  exception. Negative controls cover absent/wrong-path ledgers and changed calls.
• Validation follows nightly and deliberate frozen-candidate promotion policy.
  This patch packages source-validation maintenance; no new model-eval result or
  broader lexical/dataflow guarantee is claimed.
• FW01 source evidence.