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/mode/mod.rs

@@ -0,0 +1,73 @@
+use serde::{Deserialize, Serialize};
+
+pub mod agents;
+pub mod bash;
+pub mod editor;
+pub mod effort;
+pub mod help;
+pub mod key_input;
+pub mod loading;
+pub mod mcp;
+pub mod onboard;
+pub mod onboard_provider;
+pub mod picker;
+pub mod quit_confirm;
+pub mod rewind;
+pub mod security;
+pub mod session_hub;
+pub mod settings;
+pub mod todo;
+pub mod workflow;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ModeKind {
+    Chat,
+    Agents,
+    Bash,
+    Workflow,
+    Help,
+    Settings,
+    SessionHub,
+    QuitConfirm,
+    Onboard,
+    OnboardProvider,
+    Picker,
+    KeyInput,
+    Editor,
+    Effort,
+    Mcp,
+    Security,
+    Todo,
+    Rewind,
+    Loading,
+}
+
+impl ModeKind {
+    pub fn name(&self) -> &'static str {
+        match self {
+            ModeKind::Chat => "Chat",
+            ModeKind::Agents => "Agents",
+            ModeKind::Bash => "Bash",
+            ModeKind::Workflow => "Workflow",
+            ModeKind::Help => "Help",
+            ModeKind::Settings => "Settings",
+            ModeKind::SessionHub => "SessionHub",
+            ModeKind::QuitConfirm => "QuitConfirm",
+            ModeKind::Onboard => "Onboard",
+            ModeKind::OnboardProvider => "OnboardProvider",
+            ModeKind::Picker => "Picker",
+            ModeKind::KeyInput => "KeyInput",
+            ModeKind::Editor => "Editor",
+            ModeKind::Effort => "Effort",
+            ModeKind::Mcp => "MCP",
+            ModeKind::Security => "Security",
+            ModeKind::Todo => "Todo",
+            ModeKind::Rewind => "Rewind",
+            ModeKind::Loading => "Loading",
+        }
+    }
+
+    pub fn is_overlay(self) -> bool {
+        !matches!(self, ModeKind::Chat | ModeKind::Agents | ModeKind::Bash | ModeKind::Workflow)
+    }
+}