Add support for custom view in FrontendScreen

[TimoPtr]

Summary

Add support for custom view coming from the WebView into the FrontendScreen. It is built on top of the ExoPlayer support PR #6771.

Checklist

• New or updated tests have been added to cover the changes following the testing guidelines.
• The code follows the project's code style and best_practices.
• The changes have been thoroughly tested, and edge cases have been considered.
• Changes are backward compatible whenever feasible. Any breaking changes are documented in the changelog for users and/or in the code for developers depending on the relevance.

[Copilot]

Pull request overview

This PR adds support for rendering a WebView-provided “custom view” (typically fullscreen HTML5 video) inside the Compose-based FrontendScreen, building on the earlier ExoPlayer overlay work.

Changes:

• Extend HAWebChromeClient with onShowCustomView/onHideCustomView callbacks
• Add customView to FrontendViewState.Content and propagate it from FrontendViewModel
• Render the custom view as a fullscreen Compose overlay in FrontendScreen, with unit/UI/screenshot test coverage

Reviewed changes

Copilot reviewed 8 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
app/src/main/kotlin/io/homeassistant/companion/android/util/HAWebChromeClient.kt	Adds custom view show/hide callbacks to WebChromeClient wrapper
app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendViewState.kt	Adds customView: View? to FrontendViewState.Content
app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModel.kt	Wires WebChromeClient callbacks to state updates + fullscreen events
app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendScreen.kt	Displays a fullscreen overlay for customView and adds a test tag
app/src/test/kotlin/io/homeassistant/companion/android/util/HAWebChromeClientTest.kt	Unit tests for forwarding show/hide custom view callbacks
app/src/test/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModelTest.kt	Unit tests for ViewModel state changes + fullscreen events on custom view
app/src/test/kotlin/io/homeassistant/companion/android/frontend/FrontendScreenTest.kt	Compose UI tests asserting the overlay is shown/hidden based on state
app/src/screenshotTest/kotlin/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest.kt	Adds screenshot test coverage for the custom view overlay
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_tablet_landscape_62cae397_0.png	Screenshot baseline for tablet landscape
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_tablet_2f22c4ea_0.png	Screenshot baseline for tablet
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_small_phone_66e7bbf2_0.png	Screenshot baseline for small phone
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_phone_landscape_9e00b29d_0.png	Screenshot baseline for phone landscape
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_phone_e05166be_0.png	Screenshot baseline for phone
app/src/screenshotTestFullDebug/reference/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest/FrontendScreen Content state with custom view overlay_foldable_c908f502_0.png	Screenshot baseline for foldable

[Copilot]

Pull request overview

This PR adds support for WebView “custom views” (typically fullscreen HTML5 video views provided via WebChromeClient.onShowCustomView) to the Compose-based FrontendScreen, building on the earlier FrontendScreen ExoPlayer overlay work.

Changes:

• Extend HAWebChromeClient with onShowCustomView / onHideCustomView callbacks and add unit tests for them
• Add a customView overlay to FrontendScreenContent using AndroidView, with Compose UI tests + screenshot test coverage
• Refactor FrontendViewModel to provide a createWebChromeClient(...) factory so the custom view can stay UI-scoped (avoiding ViewModel leaks) while still emitting fullscreen events

Reviewed changes

Copilot reviewed 7 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
app/src/main/kotlin/io/homeassistant/companion/android/util/HAWebChromeClient.kt	Adds forwarding for WebView custom view show/hide callbacks
app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModel.kt	Introduces createWebChromeClient(...) to wire fullscreen + permission/JS confirm handling without storing Views in VM state
app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendScreen.kt	Adds UI-scoped customView state and renders it as a fullscreen overlay via AndroidView
app/src/test/kotlin/io/homeassistant/companion/android/util/HAWebChromeClientTest.kt	Adds unit tests for custom view callbacks
app/src/test/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModelTest.kt	Adds tests ensuring custom view callbacks + fullscreen events are emitted via the factory client
app/src/test/kotlin/io/homeassistant/companion/android/frontend/FrontendScreenTest.kt	Adds Compose UI tests verifying the overlay appears/doesn’t appear based on customView
app/src/screenshotTest/kotlin/io/homeassistant/companion/android/frontend/FrontendScreenScreenshotTest.kt	Adds screenshot coverage for the custom view overlay
app/src/screenshotTestFullDebug/reference/...png	Adds reference images for the new screenshot test