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/mode/effort.rs

@@ -16,9 +16,3 @@ pub fn cycle_effort(state: &mut AppStateRest) {
     state.misc.effort_level = (current + 1) % EFFORT_LEVELS.len();
     state.dirty = true;
 }
-
-pub fn set_effort(state: &mut AppStateRest, level: usize) {
-    let clamped = level.min(EFFORT_LEVELS.len() - 1);
-    state.misc.effort_level = clamped;
-    state.dirty = true;
-}

src/app/mode/mod.rs

@@ -1,32 +1,10 @@
 use serde::{Deserialize, Serialize};
 
-#[expect(dead_code)]
-pub mod agents;
 pub mod bash;
-#[expect(dead_code)]
-pub mod editor;
-#[expect(dead_code)]
-pub mod effort;
-#[expect(dead_code)]
-pub mod help;
-#[expect(dead_code)]
-pub mod key_input;
-#[expect(dead_code)]
-pub mod loading;
-#[expect(dead_code)]
-pub mod mcp;
-#[expect(dead_code)]
-pub mod onboard;
-#[expect(dead_code)]
-pub mod onboard_provider;
 pub mod quit_confirm;
-#[expect(dead_code)]
-pub mod rewind;
 pub mod security;
 pub mod settings;
 pub mod todo;
-#[expect(dead_code)]
-pub mod workflow;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum ModeKind {
@@ -48,31 +26,3 @@ pub enum ModeKind {
     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::QuitConfirm => "QuitConfirm",
-            ModeKind::Onboard => "Onboard",
-            ModeKind::OnboardProvider => "OnboardProvider",
-            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)
-    }
-}