feat: Comment edit/delete, auto-link URLs, markdown tables, mobile fixes

- Add comment edit/delete functionality (owner or admin can modify)
- Add edit/delete buttons to comments in TicketView
- Create update_comment.php and delete_comment.php API endpoints
- Add updateComment() and deleteComment() methods to CommentModel
- Show "(edited)" indicator on modified comments
- Add migration script for updated_at column

- Auto-link URLs in plain text comments (non-markdown)
- Add markdown table support with proper HTML rendering
- Preserve code blocks during markdown parsing

- Fix mobile UI elements showing on desktop (add display:none defaults)
- Add mobile styles for CreateTicketView form elements
- Stack status-priority-row on mobile devices

- Update cache busters to v20260124e
- Update Claude.md and README.md documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/add_comment_updated_at.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Migration script to add updated_at column to ticket_comments table
+ * Run this on the production server: php scripts/add_comment_updated_at.php
+ */
+
+require_once dirname(__DIR__) . '/config/config.php';
+
+echo "Adding updated_at column to ticket_comments table...\n";
+
+try {
+    $conn = new mysqli(
+        $GLOBALS['config']['DB_HOST'],
+        $GLOBALS['config']['DB_USER'],
+        $GLOBALS['config']['DB_PASS'],
+        $GLOBALS['config']['DB_NAME']
+    );
+
+    if ($conn->connect_error) {
+        throw new Exception("Connection failed: " . $conn->connect_error);
+    }
+
+    // Check if column already exists
+    $result = $conn->query("SHOW COLUMNS FROM ticket_comments LIKE 'updated_at'");
+
+    if ($result->num_rows > 0) {
+        echo "Column 'updated_at' already exists in ticket_comments table.\n";
+    } else {
+        // Add the column
+        $sql = "ALTER TABLE ticket_comments ADD COLUMN updated_at TIMESTAMP NULL DEFAULT NULL AFTER created_at";
+
+        if ($conn->query($sql)) {
+            echo "Successfully added 'updated_at' column to ticket_comments table.\n";
+        } else {
+            throw new Exception("Failed to add column: " . $conn->error);
+        }
+    }
+
+    $conn->close();
+    echo "Done!\n";
+
+} catch (Exception $e) {
+    echo "Error: " . $e->getMessage() . "\n";
+    exit(1);
+}