Implement chat and markdown views, enhance status bar, and add workflow panel

- Added `chat.rs` for rendering chat messages with timestamps and roles.
- Introduced `markdown.rs` for rendering markdown content with styling.
- Created `status.rs` to display the application status bar with session and message counts.
- Developed `workflow.rs` to show the current workflow status, including tool calls and active jobs.
- Established a `theme.rs` for centralized color management across the UI.
- Updated `mod.rs` to include new modules and manage rendering logic.

src/app/state/mod.rs

@@ -0,0 +1,8 @@
+pub mod input;
+pub mod misc;
+pub mod rest;
+pub mod runtime;
+pub mod scroll;
+pub mod diff;
+pub mod snapshot;
+pub mod types;