DiffLens v0.3.0

First portfolio release. Private, local-only text comparison with unified/split/inline views, moved-line detection, JSON normalization, history, patch/Markdown export, and a change-marker rail.\n\nVerified on the release commit: 67 unit checks passed; the browser smoke suite passed against the exact 16-file ZIP; archive integrity and full-history secret scanning passed.\n\nSHA-256: 6ccb723e995c529dbb71d72e22badea7eef9e3792937f856830348150dd4a1c3