Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

crates/agent/src/agent_profile.rs

@@ -90,7 +90,7 @@ impl AgentProfile {
             return false;
         };
 
-        return Self::is_enabled(settings, source, tool_name);
+        Self::is_enabled(settings, source, tool_name)
     }
 
     fn is_enabled(settings: &AgentProfileSettings, source: ToolSource, name: String) -> bool {

crates/agent/src/thread_store.rs

@@ -42,7 +42,7 @@ use std::{
 use util::ResultExt as _;
 
 pub static ZED_STATELESS: std::sync::LazyLock<bool> =
-    std::sync::LazyLock::new(|| std::env::var("ZED_STATELESS").map_or(false, |v| !v.is_empty()));
+    std::sync::LazyLock::new(|| std::env::var("ZED_STATELESS").is_ok_and(|v| !v.is_empty()));
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub enum DataType {

crates/agent/src/tool_use.rs

@@ -275,7 +275,7 @@ impl ToolUseState {
     pub fn message_has_tool_results(&self, assistant_message_id: MessageId) -> bool {
         self.tool_uses_by_assistant_message
             .get(&assistant_message_id)
-            .map_or(false, |results| !results.is_empty())
+            .is_some_and(|results| !results.is_empty())
     }
 
     pub fn tool_result(