feat: implement Nova Base + Pezkuwi Overlay architecture

- Add Nova utils as git submodule (nova-base/)
- Create pezkuwi-overlay/ for Pezkuwi-specific configs
- Add merge-chains.py script to combine Nova + Pezkuwi
- Add update-all.sh for easy syncing
- Add ARCHITECTURE.md documentation

This architecture allows automatic sync with Nova's Polkadot
ecosystem updates while maintaining Pezkuwi customizations.

Pezkuwi chains: 3 (priority)
Nova chains: 98 (auto-synced)

scripts/update-all.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+# Pezkuwi Wallet Utils - Update Script
+# Updates Nova submodule and re-merges all chain configs
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+ROOT_DIR="$(dirname "$SCRIPT_DIR")"
+
+echo "╔══════════════════════════════════════════════════╗"
+echo "║     Pezkuwi Wallet Utils - Full Update           ║"
+echo "╚══════════════════════════════════════════════════╝"
+
+cd "$ROOT_DIR"
+
+# Step 1: Update Nova submodule
+echo ""
+echo "Step 1: Updating Nova submodule..."
+git submodule update --remote nova-base
+echo "✓ Nova updated to latest"
+
+# Step 2: Show Nova version info
+echo ""
+echo "Step 2: Nova version info..."
+cd nova-base
+NOVA_COMMIT=$(git rev-parse --short HEAD)
+NOVA_DATE=$(git log -1 --format=%ci)
+echo "  Commit: $NOVA_COMMIT"
+echo "  Date: $NOVA_DATE"
+cd ..
+
+# Step 3: Merge chains
+echo ""
+echo "Step 3: Merging chain configs..."
+python3 scripts/merge-chains.py --version v22
+
+# Step 4: Summary
+echo ""
+echo "╔══════════════════════════════════════════════════╗"
+echo "║                 Update Complete!                 ║"
+echo "╚══════════════════════════════════════════════════╝"
+echo ""
+echo "Nova version: $NOVA_COMMIT ($NOVA_DATE)"
+echo ""
+echo "Next steps:"
+echo "  1. Review changes: git diff chains/"
+echo "  2. Test the wallet"
+echo "  3. Commit: git add -A && git commit -m 'chore: sync with Nova $NOVA_COMMIT'"