Security, perf, and robustness hardening (audit-driven) + README refresh

README.md

@@ -12,14 +12,46 @@ By [21st.dev](https://21st.dev) team
 
 Enhancements added in this fork on top of upstream:
 
+### Workflow & UI
+
+- **Split View with Drag-to-Split** - Drag a sub-chat from the sidebar to create or extend a split-view layout; per-pane close button in the title bar
+- **Cmd+Shift+T: New Sub-Chat in Split** - Dedicated shortcut (and tooltip) that opens a new sub-chat directly into split view
+- **Sortable Sidebar** - Reorder chats in the sidebar via drag-and-drop (@dnd-kit), with a grab-cursor + grip-handle hint on hover
+- **Draggable Tab Bar** - Native HTML5 drag-and-drop on tabs with an insertion marker; split pairs stay locked
+- **Queue Reorder** - Drag to reorder queued messages before they're sent
+- **Text-Selection Copy Popover** - Copy button appears when you highlight text inside a chat message
+- **Optimistic Sub-Chat Creation** - New sub-chats appear instantly and roll back on RPC failure
 - **Per-Mode Thinking Effort** - Set Claude's thinking budget independently for Plan and Agent modes
+- **Per-Mode Default Models** - Configure a default model per mode with automatic switching on mode change
 - **Usage Statistics** - Built-in page showing Claude + Codex token and cost tracking
-- **Per-Mode Default Models** - Configure default model per mode with automatic switching on mode change
-- **Latest Claude Models** - Opus 4.7 and updated model list including latest Claude releases
 - **Wider Chat Column** - Expanded chat area (max-w-4xl) for better readability
-- **Windows Git Path Fix** - POSIX-normalized git paths so the sidebar tree view works on Windows
 - **Enter / Shift+Enter Swap** - Enter submits, Shift+Enter inserts a newline (matches common conventions)
 
+### Git, PRs & Worktrees
+
+- **PR Widget with Comments** - Inline PR status, comments, and details alongside the chat
+- **Branch Switcher Popover** - Switch branches from a popover in the changes panel; PR chip refreshes immediately on switch (no more 30-second polling wait)
+- **PR Auto-Refresh on Commit/Push** - PR status updates automatically when you commit or push from the app
+- **Two-Column Commit Diff** - Side-by-side diff view for commit contents
+- **Pull & Push Recovery Dialog** - When `git push` fails because the remote is ahead, a one-click dialog auto-stashes, rebases, and re-pushes instead of surfacing a raw "non-fast-forward" error
+- **Worktree Deletion Safety** - Worktrees are only removed when you explicitly opt in via the archive flow with the "Delete worktree" checkbox; project delete and app startup no longer auto-remove worktrees
+
+### Models
+
+- **Latest Claude Models** - Opus 4.7 and updated model list including the latest Claude releases
+- **Sonnet 4.6 1M Context** - Full 1M-token context for Sonnet (`sonnet[1m]`) alongside the existing Opus 1M, with an amber "1M · higher cost" badge in the selector
+- **One-Click 1M Recovery** - On rate-limit or context errors against a 1M model, the toast action becomes "Switch to \<base model\>" — one click moves the sub-chat back to the 200K variant
+- **GPT-5.4 & GPT-5.4 Mini** - Latest Codex models registered as the default; gpt-5.3-codex remains available
+
+### Stability & Polish
+
+- **Rich Tool Rendering** - Proper icons and labels for `Skill`, `ScheduleWakeup`, `EnterPlanMode`, `Cron*`, `Monitor`, `PushNotification`, `TaskOutput`/`TaskStop`, `EnterWorktree`/`ExitWorktree`, `RemoteTrigger`, and `ToolSearch` (previously rendered as plain text)
+- **Stream Wedge Timeout** - 90-second first-chunk timeout aborts and surfaces a `STREAM_WEDGE` error instead of hanging the UI indefinitely
+- **Crash Auto-Recovery** - App-root error boundary + one-shot auto-reload (10s debounce) for IPC race crashes, so you get a visible error state instead of a black screen
+- **Session Abort on Delete** - In-flight Claude sessions are aborted before their workspace is removed on project/chat/sub-chat delete
+- **Lazy Archive Popover** - Archive queries no longer fire until the popover opens, reducing startup network chatter
+- **Windows Git Path Fix** - POSIX-normalized git paths so the sidebar tree view works on Windows
+
 ---
 
 ## Highlights

drizzle/0009_wise_rumiko_fujikawa.sql

@@ -0,0 +1,3 @@
+CREATE INDEX `chats_project_id_idx` ON `chats` (`project_id`);--> statement-breakpoint
+CREATE INDEX `sub_chats_chat_id_idx` ON `sub_chats` (`chat_id`);--> statement-breakpoint
+CREATE INDEX `sub_chats_stream_id_idx` ON `sub_chats` (`stream_id`);