* Add BitChatBrandButton and BitChatIcon
Add a dedicated brand button component and custom vector icon to the UI library. Refactor the chat header to use this component, replacing the previous modifier-based multi-click implementation.
* **BitChatBrandButton**: A new Composable that encapsulates single and triple click detection logic using coroutine delays and tap counting.
* **BitChatIcon**: A custom pixel-style `ImageVector` representing the brand.
* **ChatHeader**: Updated to use the new brand button and included a visual separator (`/`) in the layout.
* **ModifierExt.kt**: Removed the `singleOrTripleClickable` extension as its functionality is now handled internally by the brand button component.
* ui: refactor text messages to two-row layout
Refactor the message list items to use a two-row layout for standard text messages, while preserving the legacy compact format for system messages.
* **UI Formatting**: Added `formatTextMessageSender`, `formatTextMessageMetadata`, and `formatTextMessageBody` in `ChatUIUtils.kt` to separate the rendering of sender info, timestamps/PoW, and message content.
* **Layout Change**: Replaced the single-block `Text` component with a `Column` containing a `Row` (Sender + Metadata) and a message body `Text` block for standard messages.
* **Interaction**: Updated `pointerInput` and `detectTapGestures` to handle nickname clicks in the header row and geohash/URL clicks within the message body row.
* **Styling**: Refined `appendIOSFormattedContent` to support a `contentColor` parameter and applied specific font weights and colors (e.g., orange for self-messages) to match the platform's design language.
* **System Messages**: Explicitly kept messages where `sender == "system"` on the original compact layout.
* refactor(ui): extract annotated text pointer handling
* fix(ui): address chat redesign review feedback
* fix(ui): align PoW animation with text layout
* refactor(ui): extract message interaction helpers
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Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>
