Add Android web app manifest and Sensorius launcher icons

[mot-yelraf]

Summary

Android Home Screen additions now have explicit Sensorius launcher metadata: a web-app manifest, 192px and 512px standard PNG icons, and a padded maskable icon. The dashboard and shared template link the manifest and a PNG favicon fallback. Icons are reproducibly rasterized from the existing SVG logo.

The user guide and PDF explain Android setup and replacing cached shortcut icons. Version: v0.26.252.5.

Verification

• npm run validate:pr: 22 Chromium tests passed, including manifest parsing, serving MIME type, start URL/scope, and icon loading/dimensions.
• python3 -m pytest testApparatus/test_compile_python.py -q: passed.
• npm run docs:pdf: passed; affected pages visually checked.
• git diff --check: passed.
• Host: macOS, Python 3.13.9. Browser tests used the isolated Playwright fixture; no live MQTT broker or direct hardware required.

Contributor checklist

• This pull request is focused on one logical change.
• I added or updated tests for behavior changes.
• I updated the canonical documentation when behavior or configuration changed.
• I did not commit credentials, private runtime configuration, databases, or logs.
• I preserved compatibility-sensitive MQTT, settings, switch identity, and persistence behavior, or documented an intentional break.

Maintainer verification

• Required remote checks pass: Python 3.11/3.13 compilation and regression suite with coverage floor.
• npm run validate:pr passes on a trusted host when the change can affect rendered UI behavior.
• Hardware-, broker-, onboarding-, and platform-specific behavior not covered remotely is recorded below.

Residual risk or unverified areas

No Android device is available, so actual Home Screen installation, launcher cropping, and cached icon replacement were not device-tested. The user authorized proceeding with this limitation. Browser and connection policies can offer a local HTTP hub as a shortcut instead of a standalone installed app. This change does not add offline support.