[pengzhendong]

Summary

• Add native Spanish–English code-mixed ITN (es_en), reusing the existing standalone Spanish and English ITN rules. No TN pipeline is introduced.
• Keep source text in raw fields. Local rules add code-mixed time, whitelist and prefixed forms, plus English Indian numbering and measure units, without modifying the standalone grammars.
• Register the ITN-only CLI entry (with --cased, default false), package data, configuration-aware cache tests and README. TN rejects es_en.

Test plan

• All 976 original fixture lines (22 files) retained verbatim: 749 default and 227 cased cases
• Hand-written code-mixed, raw-field, escaping, whitespace and n-best/mapping cases
• CLI and cache registration regressions with NeMo imports blocked
• Full project suite on the merged master baseline (21943 passed, NeMo imports blocked)
• flake8 tn itn and git diff --check