chore(deps): update electron to v42 and migrate to async safeStorage

[afonsojramos]

Summary

• Bumps electron from 41.5.0 to 42.0.0.
• Migrates src/main/handlers/storage.ts to the new async safeStorage.encryptStringAsync / decryptStringAsync introduced in electron/electron#49054, which uses os_crypt_async to discover Linux secret service providers via D-Bus instead of relying on XDG_CURRENT_DESKTOP.
• Fixes "Encryption is not available" on Linux tiling WMs (Hyprland, Sway, i3, etc.) — supersedes the D-Bus workaround proposed in fix: Improve password store detection on Linux tiling WMs #2785, which can now be closed.

Test plan

• `pnpm install` clean on Electron 42.0.0
• `pnpm test` — 933 tests / 133 files passing
• `pnpm lint:check` clean on changed files
• Manual verification of login flow on Linux Hyprland / macOS / Windows

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
40.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[afonsojramos]

@BlueManCZ can you test this branch to validate that it indeed works?