Auto-fix JSON comments and trailing commas for HTTP request bodies

Add a per-request "Automatically Fix JSON" toggle (default: on) that strips
comments and trailing commas before sending HTTP requests. When disabled,
comments are sent as-is and the editor linter flags them as errors.

- New JsonBodyEditor component with settings dropdown and dismissible banner
- Configurable JSON linter (allowComments/allowTrailingCommas) via lintExtension prop
- strip_trailing_commas pass in Rust strip_json_comments pipeline
- Fix JSON formatter pulling standalone comments onto previous comma line
- Add get_bool_map helper, maybe_strip_json_comments, and related tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/yaak-templates/src/format_json.rs

@@ -11,6 +11,7 @@ pub fn format_json(text: &str, tab: &str) -> String {
     let mut new_json = "".to_string();
     let mut depth = 0;
     let mut state = FormatState::None;
+    let mut saw_newline_in_whitespace = false;
 
     loop {
         let rest_of_chars = chars.clone();
@@ -74,8 +75,8 @@ pub fn format_json(text: &str, tab: &str) -> String {
             }
             // Check if the comma handler already added \n + indent
             let trimmed = new_json.trim_end_matches(|c: char| c == ' ' || c == '\t');
-            if trimmed.ends_with(",\n") {
-                // After comma: undo the newline+indent, make comment trailing
+            if trimmed.ends_with(",\n") && !saw_newline_in_whitespace {
+                // Trailing comment on the same line as comma (e.g. "foo",// comment)
                 new_json.truncate(trimmed.len() - 1);
                 new_json.push(' ');
             } else if !trimmed.ends_with('\n') && !new_json.is_empty() {
@@ -85,6 +86,7 @@ pub fn format_json(text: &str, tab: &str) -> String {
             new_json.push_str(&comment);
             new_json.push('\n');
             new_json.push_str(tab.to_string().repeat(depth).as_str());
+            saw_newline_in_whitespace = false;
             continue;
         }
 
@@ -180,8 +182,12 @@ pub fn format_json(text: &str, tab: &str) -> String {
                     || current_char == '\t'
                     || current_char == '\r'
                 {
+                    if current_char == '\n' {
+                        saw_newline_in_whitespace = true;
+                    }
                     // Don't add these
                 } else {
+                    saw_newline_in_whitespace = false;
                     new_json.push(current_char);
                 }
             }
@@ -500,6 +506,26 @@ mod tests {
   "foo": "// not a comment",
   "bar": "/* also not */"
 }
+"#
+            .trim()
+        );
+    }
+
+    #[test]
+    fn test_comment_on_line_after_comma() {
+        assert_eq!(
+            format_json(
+                r#"{
+  "a": "aaa",
+  // "b": "bbb"
+}"#,
+                "  "
+            ),
+            r#"
+{
+  "a": "aaa",
+  // "b": "bbb"
+}
 "#
             .trim()
         );

crates/yaak-templates/src/strip_json_comments.rs

@@ -113,11 +113,67 @@ pub fn strip_json_comments(text: &str) -> String {
     }
 
     // Remove lines that are now empty (were comment-only lines)
-    result
+    let result = result
         .lines()
         .filter(|line| !line.trim().is_empty())
         .collect::<Vec<&str>>()
-        .join("\n")
+        .join("\n");
+
+    // Remove trailing commas before } or ]
+    strip_trailing_commas(&result)
+}
+
+/// Removes trailing commas before closing braces/brackets, respecting strings.
+fn strip_trailing_commas(text: &str) -> String {
+    let mut result = String::with_capacity(text.len());
+    let chars: Vec<char> = text.chars().collect();
+    let mut i = 0;
+    let mut in_string = false;
+
+    while i < chars.len() {
+        let ch = chars[i];
+
+        if in_string {
+            result.push(ch);
+            match ch {
+                '"' => in_string = false,
+                '\\' => {
+                    i += 1;
+                    if i < chars.len() {
+                        result.push(chars[i]);
+                    }
+                }
+                _ => {}
+            }
+            i += 1;
+            continue;
+        }
+
+        if ch == '"' {
+            in_string = true;
+            result.push(ch);
+            i += 1;
+            continue;
+        }
+
+        if ch == ',' {
+            // Look ahead past whitespace/newlines for } or ]
+            let mut j = i + 1;
+            while j < chars.len() && chars[j].is_whitespace() {
+                j += 1;
+            }
+            if j < chars.len() && (chars[j] == '}' || chars[j] == ']') {
+                // Skip the comma
+                i += 1;
+                continue;
+            }
+        }
+
+        result.push(ch);
+        i += 1;
+    }
+
+    result
 }
 
 #[cfg(test)]
@@ -232,4 +288,31 @@ mod tests {
 }"#
         );
     }
+
+    #[test]
+    fn test_trailing_comma_after_comment_removed() {
+        assert_eq!(
+            strip_json_comments(r#"{
+  "a": "aaa",
+  // "b": "bbb"
+}"#),
+            r#"{
+  "a": "aaa"
+}"#
+        );
+    }
+
+    #[test]
+    fn test_trailing_comma_in_array() {
+        assert_eq!(
+            strip_json_comments(r#"[1, 2, /* 3 */]"#),
+            r#"[1, 2]"#
+        );
+    }
+
+    #[test]
+    fn test_comma_inside_string_preserved() {
+        let input = r#"{"a": "hello,}"#;
+        assert_eq!(strip_json_comments(input), input);
+    }
 }