Prepare TapAuth 1.1.0 release

[devkyato]

What changed

• rewrote the README and technical guide in a concise, personal project voice
• documented the local-first NFC registration story and data flow
• promoted the accumulated offline registration work into version 1.1.0
• added narrative release notes and refreshed contribution/support guidance
• fixed corrupted characters in public documentation

Why

TapAuth had grown beyond its original tap-in/tap-out prototype, but the repository still read like a generic product page. This release explains the actual reasoning behind the local registry: registered cards should remain recognizable during MySQL outages and immediately after registration.

Impact

The application behavior is unchanged except that /system_status now reports version 1.1.0. Setup, update, privacy, and fallback behavior are easier to understand from the repository itself.

Validation

• python -m compileall -q .
• node --check script.js
• node --check hosting/app.js
• node --check hosting/firebase-config.js
• Firebase JSON validation
• python -m unittest discover -s tests -v — 15 tests passed
• git diff --check