chore(lint): extend low-risk clippy cleanup batch

- normalize numeric literals (115_200) in hardware/peripheral config paths

- remove test-only useless format! allocations in discord IDs

- simplify closures and auto-deref in browser/http/rag/peripherals

- keep behavior unchanged while reducing warning surface

src/channels/discord.rs

@@ -723,8 +723,8 @@ mod tests {
     #[test]
     fn discord_message_id_different_message_different_id() {
         // Different message IDs produce different IDs
-        let id1 = format!("discord_123456789012345678");
-        let id2 = format!("discord_987654321098765432");
+        let id1 = "discord_123456789012345678".to_string();
+        let id2 = "discord_987654321098765432".to_string();
         assert_ne!(id1, id2);
     }