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/subagent/context.rs

@@ -4,12 +4,10 @@ use super::spawn::AgentDefinition;
 pub const REVIEWER_ALLOWED: &[&str] = &["read", "grep", "glob", "recall", "remember"];
 
 pub struct SubagentContext {
-    pub definition: AgentDefinition,
     pub system_prompt: String,
     pub allowed_tools: Vec<String>,
     pub max_steps: usize,
     pub session_dir: PathBuf,
-    pub origin: crate::app::state::types::Origin,
 }
 
 pub fn build_subagent_context(def: AgentDefinition) -> SubagentContext {
@@ -21,11 +19,9 @@ pub fn build_subagent_context(def: AgentDefinition) -> SubagentContext {
         }
     });
     SubagentContext {
-        definition: def,
         system_prompt: String::new(),
         allowed_tools,
         max_steps: 25,
         session_dir: PathBuf::new(),
-        origin: crate::app::state::types::Origin::SubAgent,
     }
 }