Fix CI lint and release reruns

[D-sudoasd]

Changes

• remove the unused GUI parser assignment reported by Ruff
• document domain-specific h, k, l notation with narrow per-file Ruff exceptions
• make tagged release publishing idempotent by updating an existing Release instead of failing when it already exists

Validation

• documentation checks passed
• Python source compilation passed
• 68 tests passed
• analytic benchmark: 45/45 checks passed
• offline demo and strict bundle verification passed
• release preflight passed
• all workflow YAML files parsed successfully

This addresses the initial public-baseline CI failure and the release job's duplicate-Release failure without changing scientific results or the existing v0.3.0 tag.