Bring in mcp-skills-plugins branch: marketplace, plugins, skills, OpenCredits, and image previews

Major release adding:
- MCP marketplace with curated registry and search across multiple registries
- Plugins and skills marketplace integration
- OpenCredits payment integration with model selection and checkout flow
- Image preview before sending (paste, file picker)
- Self-hosted Umami analytics with custom events
- Support feedback modal with Discord webhook
- Local OpenAI to Anthropic router for model routing
- Inline stop button replacing send during processing
- Improved install flow requiring Node.js 18+
- WSL env var passthrough fixes
- Better error handling and Windows compatibility

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backup.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+# Backup script for src folder
+
+# Get the directory where the script is located
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# Create backup directory if it doesn't exist
+BACKUP_DIR="$SCRIPT_DIR/backup-files"
+mkdir -p "$BACKUP_DIR"
+
+# Generate timestamp
+TIMESTAMP=$(date +"%Y-%m-%d_%H-%M-%S")
+
+# Create backup filename
+BACKUP_NAME="src-backup-$TIMESTAMP"
+
+# Copy src folder to backup
+cp -r "$SCRIPT_DIR/src" "$BACKUP_DIR/$BACKUP_NAME"
+
+echo "Backup created: $BACKUP_DIR/$BACKUP_NAME"