v0.1.2 — Math expression encoding fixes

What's Changed

Two encoding bugs fixed in math instruction blobs:

• Duplicate operands preserved — expressions like DS1 + DS1 now correctly allocate one operand slot per
  occurrence, matching Click's native encoding. Previously they were deduplicated, producing mismatched blobs.
• Parenthesis spacing normalized — (DS1 + DS2) is now automatically expanded to ( DS1 + DS2 ) on construction,
  matching Click's native format.

Also fixes the show_nicknames code path to wrap operands as <?ADDR> in the formula display field, and documents
the 68-operand editor cap discovered during native capture testing.

Full Changelog: v0.1.1...v0.1.2