feat: add optional allow_binary parameter to item handlers

Co-authored-by: aider (openai/andrew/openrouter/anthropic/claude-sonnet-4) <aider@aider.chat>

src/modes/server/common.rs

@@ -69,6 +69,8 @@ pub struct ItemContentInfo {
 #[derive(Debug, Deserialize)]
 pub struct TagsQuery {
     pub tags: Option<String>,
+    #[serde(default)]
+    pub allow_binary: bool,
 }
 
 #[derive(Debug, Deserialize)]
@@ -79,6 +81,12 @@ pub struct ListItemsQuery {
     pub count: Option<u32>,
 }
 
+#[derive(Debug, Deserialize)]
+pub struct ItemQuery {
+    #[serde(default)]
+    pub allow_binary: bool,
+}
+
 fn check_bearer_auth(auth_str: &str, expected_password: &str) -> bool {
     auth_str.starts_with("Bearer ") && &auth_str[7..] == expected_password
 }