Show the user's avatar next to display name in the top bar when the
profile header is scrolled out of view. Remove redundant center spinner
in favor of the existing PullToRefreshBox indicator. Overlap avatar on
banner in the edit profile sheet to match the profile view layout.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Implement a full profile screen reachable by tapping any user avatar.
Includes banner/avatar display, follow/unfollow, mute/unmute, bot badge,
verification badge, follower/following/post stats, bio, feed filter tabs
(posts, replies, media, video), pagination, and a profile editor bottom
sheet for own profile (edit display name, bio, avatar, banner). Also fix
ComposeView spell check by switching keyboard type from Email to Text.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Update `MainView` to use `TopAppBar` with `enterAlwaysScrollBehavior` instead of the flexible variant. Additionally, provide a consistent `ColorPainter` placeholder using the `surfaceVariant` color for `AsyncImage` components across `MainView`, `SkeetView`, `ComposeView`, and other gallery/list items to improve the loading experience.

Deleting the toolchainVendor line entirely so Gradle accepts any
JDK 21, including the Nix-provided OpenJDK.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The gradle-daemon-jvm.properties requires JetBrains JDK which isn't
available in CI. Patch to ADOPTIUM at build time and set JAVA_HOME
explicitly to the Nix-provided JDK.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The foojay resolver tries to download a JetBrains JDK 21 which
fails to unpack in CI. Disable auto-download so Gradle uses the
Nix-provided jdk21_headless instead.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>