Refactor IPC and DTO structures; remove unused code and streamline message handling

- Removed unused structs and methods from `response.rs`, `usage.rs`, and `client.rs`.
- Simplified `Connection` handling in `conn.rs` to only support Unix sockets.
- Updated `IpcServer` to exclusively use Unix sockets and removed TCP handling.
- Cleaned up `editlog.rs` by removing loading and recent entry methods.
- Refactored `memory.rs` to eliminate unused functions related to lesson promotion and retrospective creation.
- Enhanced `search.rs` to support multiple search providers and improved error handling.
- Updated chat view logic to simplify message display and improve user experience.
- Removed deprecated modules and constants from various files to streamline the codebase.

src/app/bgbash/control.rs

@@ -28,11 +28,3 @@ pub fn bash_kill(id: &str) -> anyhow::Result<()> {
         anyhow::bail!("bash job '{}' not found", id)
     }
 }
-
-pub fn register_bash_job(job: BashJob) -> String {
-    let id = job.id.clone();
-    if let Ok(mut map) = bash_jobs_map().lock() {
-        map.insert(id.clone(), job);
-    }
-    id
-}

src/app/bgbash/job.rs

@@ -5,20 +5,16 @@ use std::io::BufRead;
 
 pub struct BashJob {
     pub id: String,
-    pub command: String,
-    pub started_at: i64,
     pub output_rx: mpsc::Receiver<String>,
     pub exit_code: Option<i32>,
-    pub handle: Option<thread::JoinHandle<()>>,
 }
 
 pub fn spawn_bash_job(command: String) -> BashJob {
     let id = uuid::Uuid::new_v4().to_string();
-    let started_at = chrono::Utc::now().timestamp_millis();
     let (output_tx, output_rx) = mpsc::channel::<String>();
     let cmd = command.clone();
 
-    let handle = thread::spawn(move || {
+    let _handle = thread::spawn(move || {
         let child = Command::new("sh")
             .arg("-c")
             .arg(&cmd)
@@ -46,11 +42,8 @@ pub fn spawn_bash_job(command: String) -> BashJob {
 
     BashJob {
         id,
-        command,
-        started_at,
         output_rx,
         exit_code: None,
-        handle: Some(handle),
     }
 }
 
@@ -68,8 +61,4 @@ impl BashJob {
             Err(_) => None,
         }
     }
-
-    pub fn is_running(&self) -> bool {
-        self.exit_code.is_none()
-    }
 }