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/model/memory.rs

@@ -1,8 +1,6 @@
 use std::path::{Path, PathBuf};
 use serde::{Deserialize, Serialize};
 
-use super::session::Session;
-
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Memory {
     pub name: String,
@@ -129,16 +127,6 @@ impl Memory {
             })
             .collect()
     }
-
-    pub fn load_index(memory_dir: &Path) -> Vec<String> {
-        let index_path = memory_dir.join("MEMORY.md");
-        let content = std::fs::read_to_string(index_path).unwrap_or_default();
-        content.lines().filter_map(|l| {
-            let l = l.trim();
-            if l.is_empty() || l.starts_with('#') { return None; }
-            l.split(']').next().and_then(|s| s.split('[').nth(1)).map(|s| s.to_string())
-        }).collect()
-    }
 }
 
 pub fn slug_path(memory_dir: &Path, raw: &str) -> PathBuf {
@@ -159,26 +147,6 @@ pub fn export_lessons(memory_dir: &Path, output: &Path) -> std::io::Result<()> {
     std::fs::write(output, data)?;
     Ok(())
 }
-pub fn promote_with_consensus(global_dir: &Path, lesson: &Memory) -> std::io::Result<bool> {
-    let global_path = global_dir.join("memory");
-    std::fs::create_dir_all(&global_path)?;
-    let existing = Memory::list(&global_path);
-    let slug = Memory::slugify(&lesson.name).unwrap_or_default();
-    if existing.contains(&slug) {
-        return Ok(true);
-    }
-    let consensus = lesson.outcome.as_deref() == Some("verified");
-
-    if consensus {
-        let mut promoted = lesson.clone();
-        promoted.scope = Some("global".to_string());
-        promoted.write(&global_path)?;
-        Ok(true)
-    } else {
-        Ok(false)
-    }
-}
-
 pub fn import_lessons(memory_dir: &Path, input: &Path) -> std::io::Result<usize> {
     let data = std::fs::read_to_string(input)?;
     let lessons: Vec<Memory> = serde_json::from_str(&data)
@@ -194,30 +162,6 @@ pub fn import_lessons(memory_dir: &Path, input: &Path) -> std::io::Result<usize>
     }
     Ok(imported)
 }
-pub fn auto_create_retrospective(session_dir: &Path, session: &Session) -> std::io::Result<Option<Memory>> {
-    let now = chrono::Utc::now().timestamp_millis();
-    let session_age_ms = now.saturating_sub(session.created_at);
-    if session_age_ms < 60_000 {
-        return Ok(None);
-    }
-    let retro_name = format!("retrospective-{}", session.id);
-    let retro_path = Memory::path(session_dir, &retro_name);
-    if retro_path.exists() {
-        return Ok(None);
-    }
-    let lessons: Vec<Memory> = Memory::list(session_dir)
-        .iter()
-        .filter_map(|n| Memory::read(session_dir, n).ok())
-        .filter(|m| m.kind == "lesson")
-        .collect();
-
-    if lessons.is_empty() {
-        return Ok(None);
-    }
-
-    let retrospective = create_retrospective(session_dir, session, &lessons)?;
-    Ok(Some(retrospective))
-}
 
 #[cfg(test)]
 mod tests {
@@ -386,31 +330,3 @@ mod tests {
         let _ = std::fs::remove_file(&export_path);
     }
 }
-
-pub fn create_retrospective(session_dir: &Path, session: &Session, lessons: &[Memory]) -> std::io::Result<Memory> {
-    let now = chrono::Utc::now().timestamp_millis();
-    let lessons_content: String = lessons.iter()
-        .map(|l| format!("- {}: {}", l.name, l.description))
-        .collect::<Vec<_>>()
-        .join("\n");
-    let content = format!(
-        "# Session Retrospective\n\nSession: {}\nCreated: {}\nLessons learned:\n{}\n",
-        session.title, now, lessons_content,
-    );
-    let memory = Memory {
-        name: format!("retrospective-{}", session.id),
-        description: format!("End-of-session retrospective for {}", session.title),
-        content,
-        kind: "retrospective".to_string(),
-        created_at: now,
-        updated_at: now,
-        outcome: None,
-        lifecycle: "new".to_string(),
-        scope: Some("project".to_string()),
-        before_snippet: None,
-        after_snippet: None,
-        provenances: vec![],
-    };
-    memory.write(session_dir)?;
-    Ok(memory)
-}