Prepare v1.0.0-rc.2

[enaboapps]

Closes #671

Changes

• Update the frontend, browser fallback, Tauri app, main Rust crate, startup launcher, tests, and lockfiles to 1.0.0-rc.2.
• Keep the release identity, protocol, storage, updater, and signing configuration unchanged.

Local validation

• npm run lint
• npm test: 74 frontend tests and 5 updater-feed tests
• npm run build
• Main crate formatting, Clippy with warnings denied, 238 unit tests, and 7 configuration tests
• Startup launcher formatting, Clippy, and 2 tests
• Updater signature verifier formatting, Clippy, and 2 tests
• npm audit --audit-level=high: 0 vulnerabilities
• cargo-audit 0.22.2 for all three lockfiles: no vulnerabilities