v1.2.3 — Settings docs, README, percentage fix

What's new

• 📖 Settings page overhaul — gradient banner, credential badges (JPHsystems, MIT), how-it-works section with 7 feature docs, command reference, version footer
• 📝 README — badge fixed, percentage section added, duplicates removed, dockable panel in feature table
• 💯 Percentage — 100+21% = 121, 100-21% = 79 (real calculator logic)
• 📌 Side panel — dockable persistent panel in right sidebar

File changes since v1.2.2

• Settings tab: banner + docs + credentials + commands + footer
• README: badge 1.2.3, percentage section, cleaned duplicates
• CSS: settings banner, doc rows, badges styling