eccc6cf0bf
Adds --no-dedup (default off, so dedup stays on) to skip the fuzzy near-duplicate merge pass on build and incremental merge, for operators who would rather keep distinct symbols that fuzzy-matched than pay the merge. Exact-id uniqueness is unaffected (it is a graph structural invariant, not a dedup responsibility), and the flag arms the #479 shrink guard so a surprising node drop is refused loudly. Mutually exclusive with --dedup-llm.