Release v2.0.0: migrate Hronomancer to Tauri 2

[Hronom]

Summary

• replace Electron with the latest Tauri 2 runtime and native Rust controller
• fix physical multi-monitor geometry, per-display screen analysis, and Linux click-through behavior
• reduce false-positive screen highlights and normal-load glitch noise
• add signed automatic updates and a cross-platform Tauri release workflow
• package Linux, macOS Intel/Apple Silicon, and Windows artifacts for v2.0.0

Validation

• npm ci
• npm test
• npm run type-check
• npm run build
• cargo fmt --check
• cargo check --locked in the Linux Tauri builder
• cargo clippy --locked -- -D warnings in the Linux Tauri builder
• full AppImage build with updater signature using a temporary test key
• release workflow YAML parse and git diff --check

The GUI overlay was intentionally not relaunched after the user's request to stop the broken build.