fix: lower Node.js requirement to v18, update repo before running updater

- Changed MIN_NODE_VERSION from (24, 13, 0) to (18, 0, 0) to match Claude Code requirements
- Updated uclaude_install.sh to fetch latest repo before running updater
- Rewrote uclaude_update.ps1 to require v18+ and update repo first
- Added multiple fallback methods for Node.js installation on Windows

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

claude/uclaude_install.sh

@@ -1,7 +1,18 @@
 #!/bin/bash
 # UClaude — one-line installer with full auto-install chain
 # Usage: curl -fsSL -H "Authorization: token TOKEN" https://git.sensey24.ru/aibot777/unlimitedcoding/raw/branch/master/claude/uclaude_install.sh -o /tmp/uclaude.sh && sudo bash /tmp/uclaude.sh
-set -e
+set -uo pipefail
+
+# Error handler
+error_handler() {
+    local line_no=$1
+    echo "ERROR: Command failed at line $line_no" >&2
+    echo "Last command: $BASH_COMMAND" >&2
+    echo "Exiting..." >&2
+    exit 1
+}
+
+trap 'error_handler $LINENO' ERR
 
 # Read-only access token for private repo (scoped: read:repository only)
 GITEA_TOKEN="${GITEA_TOKEN:-cadffcb0a6a3be728ac1ff619bb40c86588f6837}"
@@ -92,6 +103,12 @@ else
 fi
 
 echo ""
+echo "  Updating repo to latest version before running updater..."
+# Update repo to latest version BEFORE running updater (so we get latest MIN_NODE_VERSION fix)
+cd "$INSTALL_DIR"
+git fetch --depth 1 origin master 2>/dev/null
+git reset --hard origin/master 2>/dev/null || git pull --quiet 2>/dev/null
+
 echo "  Running updater..."
 
 # Run updater (needs root for cli.js replacement + node install)