Pure-state ECQC prime-dimensional classification v1

Complete written proof and exact replayable checkers for the pure-state prime-dimensional classification: validity iff p=2; full-Schmidt-rank counterexamples for every odd prime; sharp ratios at p=3 and p=5. The qutrit theorem has a separate complete Lean package. The full classification is not claimed Lean-complete.

Fixed source directory: research/ecqc-pure-state-counterexamples. No external human peer review or historical-priority claim is made. Corrections use a new release; frozen assets are not replaced.