Antigravity Guide, audio support, search improvements, and performance fixes

New built-in Antigravity Guide skill, audio file rendering, improved substring file search, performance optimizations, and critical bug fixes.

• Added a new built-in Antigravity Guide skill to provide helpful guidance when users ask about Antigravity.
• Added syntax highlighting for C++, Python, and Protobuf files in markdown code and diff blocks.
• Added hover tooltips to file pills in the chat and workspace views to display absolute paths and clarify workspace locations.
• Improved readability of context pills by truncating long labels and adding hover tooltips to view the full content.
• Enabled automatic saving of refreshed OAuth tokens to the OS keyring to reduce authentication prompts.
• Added support for rendering and playing audio files (.mp3,.wav,.ogg,.m4a) within the sidebar file viewer and artifact viewer.
• Added a new 'Conversation Width' setting under Appearance settings, allowing you to configure the maximum width of the conversation panel (Default, Narrow, or Wide).
• When creating a new project, Antigravity 2.0 will now notify you if a project with the same folders already exists, allowing you to quickly navigate to it.
• Added a tooltip to show the full task summary when hovering over items in the Running Items panel.
• Improved the model selector dropdown to dynamically resize and prevent truncation of long model names.
• Updated the permissions request dialog to display a clear description of the action or command being run.
• Improved response time and reliability of account status checks when Terms of Service violations are encountered.
• Improved UI responsiveness and eliminated lag when resizing the sidebar layout.
• Aligned theme colors, font sizes, text size, and line height in the chat input area to match surrounding UI density and ensure consistent rendering.
• Improved usability for touch and stylus users by increasing the size of various UI hit targets, including buttons, pills, and toolbars.
• Adjusted the diff viewer layout to provide more horizontal space for code contents.
• Added a brief delay before displaying tooltips for long conversation titles in the sidebar.
• Optimized file watching notifications to prevent visual flickering and improve performance during high-frequency file writes.
• Updated icons for built-in slash commands and redesigned mentions/slash commands menu alignment in the chat input box.
• Fixed an issue with broken text selection anchoring when adding comments to files or artifacts.
• Fixed an issue where workspace context was lost when navigating to the history page or other views.
• Fixed performance issues, rendering loops, and lag when navigating folders using the file path breadcrumbs or the file tree.
• Fixed erratic behavior and lag in slash command autocomplete during network instability.
• Improved file search in your workspace by matching substrings instead of requiring exact prefix matches.
• Fixed an issue where file search within workspaces could fail with a 'No such file or directory' error.
• Fixed an issue where allowing commands with special characters (like dots or environment variables) could trigger an infinite permission prompt loop.
• Improved command execution permission matching to support prefix-matching for build/test commands and correct handling of quoted arguments.
• Fixed issues where in-progress prompts and local history edits were discarded during navigation or permission checks.
• Fixed an issue where custom theme settings and color modes were not correctly applied on startup, including rejecting hex codes with a leading '#' symbol.
• Fixed startup issues and recurring User Account Control (UAC) prompts on Windows by registering a scheduled task and resolving access control errors on system PATH directories.
• Fixed crashes and synchronization issues when deleting persistent state across tabs.
• Improved accessibility and usability of the artifact review dialog, including contrast, tooltips, and error messaging.
• Fixed an issue where the agent was blocked from reading builtin customizations and skills due to sandbox restrictions.
• Fixed a startup race condition that could cause duplicate project folders to be created.
• Fixed a deadlock issue that could cause subagents to hang during execution.
• Fixed a potential crash when calculating token usage.