fix: claim hygiene + MIT LICENSE: remove promo drafts, tag ~70 ns REPORTED, document verify_correction limitation

[sparkainlp-x]

Fail-closed claim fixes plus a license. No C++ changes.

• LICENSE (MIT, Copyright (c) 2026 Jean-François Brisson, Spark AI NLP). The repo previously had none.
• Removed promotional drafts from public docs: docs/newsletter_quantum_edge.md, docs/linkedin_review.md, docs/quantum_magazine_feature.md. They contained untagged or unsupported claims ("400 MHz", "70.5 ns (Validated)", "Timing Closure Ready", "cryostat-connected hardware", "prête pour le contrôle quantique actif", "private repository"). Local copies are kept outside the repo. Note: they remain in git history.
• docs/scientific_review.md: byline relabelled "AI-assisted internal review (Manus AI), not independent peer review"; the 70–76 ns / 81–87 ns figures tagged REPORTED; host/conditions unspecified.
• README: English summary with an evidence-status table (~70 ns micro-benchmark = REPORTED, host/conditions unspecified, not decode latency; HLS timing TARGET/UNRUN; HIL UNRUN) and Known limitations: verify_correction() always returns true, so any HIL FER would be 0 by construction. The French section keeps its content, with the HIL section marked UNRUN.

Overlap: open PR #2 adds a PERFORMANCE.md with "~187 ns median". Per CLAIM_HYGIENE, it needs a REPORTED tag plus host details before merging.