[vitormattos]

Summary

Starts #342 on the Akaunting module side.

• maps cancellation choices to the official e101101 reason codes 1, 2 and 9;
• validates the justification locally at 15–255 characters;
• stops concatenating the localized reason label into xMotivo;
• adds HTML min/max constraints to both cancellation surfaces;
• keeps a transitional fallback to the legacy library method until fix: model official NFS-e cancellation reasons nfse-php#92 is merged.

Dependency

Depends on LibreCodeCoop/nfse-php#92 for the structured cancelWithReason() transport contract. After that PR lands, this branch should pin/rebuild the scoped runtime and remove the compatibility fallback.

Remaining work before merge

• shared frontend counter/disabled-state logic for both forms;
• regression tests for 14/15/255/256 characters and reason-code mapping;
• Playwright coverage;
• update the scoped nfse-php dependency after fix: fallback tpRetPisCofins when CSLL retention is zero #92 merges.

Fixes #342.