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>

Claude.md

@@ -14,6 +14,8 @@
 - Collapsible Sidebar, Kanban Card View, Inline Ticket Preview
 - Mobile Responsive Design, Ticket Linking in Comments
 - Admin Pages (Templates, Workflow, Recurring, Custom Fields, User Activity, Audit Log, API Keys)
+- Comment Edit/Delete (owner or admin can modify their comments)
+- Markdown Tables Support, Auto-linking URLs in Comments
 
 ## Project Overview
 
@@ -51,6 +53,7 @@ Controllers → Models → Database
 │   ├── bulk_operation.php                # POST: Bulk operations - admin only
 │   ├── check_duplicates.php              # GET: Check for duplicate tickets
 │   ├── delete_attachment.php             # POST/DELETE: Delete attachment
+│   ├── delete_comment.php                # POST: Delete comment (owner/admin)
 │   ├── export_tickets.php                # GET: Export tickets to CSV/JSON
 │   ├── generate_api_key.php              # POST: Generate API key (admin)
 │   ├── get_template.php                  # GET: Fetch ticket template
@@ -60,6 +63,7 @@ Controllers → Models → Database
 │   ├── manage_workflows.php              # CRUD: Workflow rules (admin)
 │   ├── revoke_api_key.php                # POST: Revoke API key (admin)
 │   ├── ticket_dependencies.php           # GET/POST/DELETE: Ticket dependencies
+│   ├── update_comment.php                # POST: Update comment (owner/admin)
 │   ├── update_ticket.php                 # POST: Update ticket (workflow validation)
 │   └── upload_attachment.php             # GET/POST: List or upload attachments
 ├── assets/