fix(module): preserve persisted text-before-tool order for tag-mutated assistant text — codec appended unmatched mutated text after tool_use, tripping Anthropic's prefill validator on final assistants (ENGRAM 400s); positional native matching now requires whole-vector agreement, step-finish ignored in CK projection (TS parity)

Co-Authored-By: Alfonso <alfonso@cortexkit.io>