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/model/msglog/query.rs

@@ -0,0 +1,68 @@
+use rusqlite::{Connection, params};
+use anyhow::Result;
+use crate::dto::chat::message::{ChatMessage, Role};
+
+pub fn insert_message(conn: &Connection, session_id: &str, msg: &ChatMessage) -> Result<i64> {
+    let content = msg.content.as_deref();
+    let tool_call_id = msg.tool_call_id.as_deref();
+    let tool_name = msg.name.as_deref();
+    let tool_arguments = msg.tool_calls.as_ref().map(|calls| {
+        serde_json::to_string(calls).unwrap_or_default()
+    });
+    let created_at = chrono::Utc::now().timestamp_millis();
+    let role_str = match msg.role {
+        Role::User => "user",
+        Role::Assistant => "assistant",
+        Role::System => "system",
+        Role::Tool => "tool",
+    };
+    conn.execute(
+        "INSERT INTO messages (session_id, role, content, tool_call_id, tool_name, tool_arguments, created_at) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)",
+        params![session_id, role_str, content, tool_call_id, tool_name, tool_arguments, created_at],
+    )?;
+    Ok(conn.last_insert_rowid())
+}
+
+pub fn query_messages(conn: &Connection, session_id: &str, limit: usize, offset: usize) -> Result<Vec<ChatMessage>> {
+    let mut stmt = conn.prepare(
+        "SELECT role, content, tool_call_id, tool_name, tool_arguments FROM messages WHERE session_id = ?1 ORDER BY id ASC LIMIT ?2 OFFSET ?3"
+    )?;
+    let rows = stmt.query_map(params![session_id, limit as i64, offset as i64], |row| {
+        let role_str: String = row.get(0)?;
+        let content: Option<String> = row.get(1)?;
+        let tool_call_id: Option<String> = row.get(2)?;
+        let tool_name: Option<String> = row.get(3)?;
+        let tool_arguments: Option<String> = row.get(4)?;
+        let role = match role_str.as_str() {
+            "user" => Role::User,
+            "assistant" => Role::Assistant,
+            "system" => Role::System,
+            "tool" => Role::Tool,
+            _ => Role::User,
+        };
+        let tool_calls = tool_arguments.and_then(|args| {
+            serde_json::from_str(&args).ok()
+        });
+        Ok(ChatMessage {
+            role,
+            content,
+            tool_calls,
+            tool_call_id,
+            name: tool_name,
+        })
+    })?;
+    let mut messages = Vec::new();
+    for row in rows {
+        messages.push(row?);
+    }
+    Ok(messages)
+}
+
+pub fn count_messages(conn: &Connection, session_id: &str) -> Result<i64> {
+    let count: i64 = conn.query_row(
+        "SELECT COUNT(*) FROM messages WHERE session_id = ?1",
+        params![session_id],
+        |row| row.get(0),
+    )?;
+    Ok(count)
+}