feat: implement prompt auto-formatter function

- Splits text by lines and cleans up tags separated by commas
- Removes redundant spaces and empty tags
- Ensures each valid line ends with a comma and space
- Preserves empty lines for readability

web/js/utils.js

@@ -654,3 +654,54 @@ export function getScrollbarWidth() {
 
     return _cachedScrollbarWidth;
 }
+
+/**
+ * Format the prompt text: add a comma and space after each tag, and remove extra spaces.
+ * Preserve special syntax such as weights (tag:1.2), parentheses, and wildcards.
+ * @param {string} text - The original text.
+ * @returns {string} - The formatted text.
+ */
+export function formatPromptText(text) {
+  if (!text || text.trim().length === 0) return text;
+
+  // Split text into individual lines for processing
+  const lines = text.split('\n');
+  const formattedLines = [];
+
+  for (const line of lines) {
+    const trimmedLine = line.trim();
+
+    // Keep empty lines unchanged
+    if (trimmedLine.length === 0) {
+      formattedLines.push('');
+      continue;
+    }
+
+    // Split the line by commas into raw tag segments
+    const rawTags = trimmedLine.split(',');
+
+    const cleanedTags = [];
+    for (const tag of rawTags) {
+      // Trim spaces around each tag
+      const trimmedTag = tag.trim();
+
+      // Keep only non-empty tags
+      if (trimmedTag.length > 0) {
+        cleanedTags.push(trimmedTag);
+      }
+    }
+
+    // Rejoin cleaned tags with ", "
+    let formattedLine = cleanedTags.join(', ');
+
+    // Add a trailing comma and space if the line contains valid tags
+    if (formattedLine.length > 0) {
+      formattedLine += ', ';
+    }
+
+    formattedLines.push(formattedLine);
+  }
+
+  // Rejoin all lines with newline characters
+  return formattedLines.join('\n');
+}