feat: v1.1 portable architecture (app/data separation)

New directory structure:
- app/core/ = OpenClaw program
- app/runtime/ = Node.js
- data/ = user config, memory, backups (never overwritten on upgrade)
- system/ = migration scripts

Features:
- Auto port detection (18789-18799)
- macOS Gatekeeper auto-fix (xattr quarantine removal)
- Windows UTF-8 BOM + CRLF encoding
- Config auto-migration on startup
- Platform-specific packages (Mac ARM64 + Windows x64)

portable/migrate.js

@@ -0,0 +1,33 @@
+#!/usr/bin/env node
+// U-Claw config migration script
+// Runs on every startup to ensure config compatibility
+
+const fs = require('fs');
+const path = require('path');
+
+const dataDir = process.argv[2] || path.join(__dirname, '..', 'data');
+const configPath = path.join(dataDir, 'config.json');
+
+if (!fs.existsSync(configPath)) process.exit(0);
+
+try {
+    const config = JSON.parse(fs.readFileSync(configPath, 'utf8'));
+
+    // Ensure gateway section exists
+    if (!config.gateway) {
+        config.gateway = { mode: 'local', auth: { token: 'uclaw' } };
+    }
+
+    // Ensure auth token exists
+    if (!config.gateway.auth || !config.gateway.auth.token) {
+        config.gateway.auth = { token: 'uclaw' };
+    }
+
+    // Future migrations go here:
+    // if (!config._version) { config._version = '1.1'; ... }
+
+    fs.writeFileSync(configPath, JSON.stringify(config, null, 2));
+} catch (e) {
+    // Don't crash on migration errors
+    console.error('Migration warning:', e.message);
+}