fix: implement blacklist filtering for broken RPC chains

- Add blocked-chains.json with DNS-failing endpoints (AlephZero, InvArch, Quartz, Passet Hub Testnet)
- Update merge-chains.py to filter PAUSED chains, testnets (except Pezkuwi), and broken RPCs
- Reduce chain count from 102 to 86 (4 Pezkuwi + 82 working Nova chains)
- This fixes staking page not loading due to DNS resolution failures

scripts/merge-chains.py

@@ -3,14 +3,17 @@
 Pezkuwi Wallet Chain Config Merger
 
 This script merges Nova's chain configurations with Pezkuwi-specific chains.
-Nova configs are used as the base, Pezkuwi chains are prepended (priority).
+Uses a blacklist to exclude broken/paused chains.
 
 Usage:
-    python3 merge-chains.py [--version v22] [--output chains/v22/chains.json]
+    python3 merge-chains.py [--version v22] [--full] [--update]
+
+Options:
+    --full    Include ALL Nova chains (including broken ones) - NOT recommended
+    --update  Update Nova submodule first
 """
 
 import json
-import os
 import argparse
 from pathlib import Path
 
@@ -21,6 +24,26 @@ NOVA_BASE = ROOT_DIR / "nova-base"
 PEZKUWI_OVERLAY = ROOT_DIR / "pezkuwi-overlay"
 OUTPUT_DIR = ROOT_DIR / "chains"
 
+# Chains with known broken RPC endpoints
+BROKEN_CHAIN_KEYWORDS = [
+    'aleph zero',
+    'alephzero',
+    'quartz',
+    'invarch',
+]
+
+# These chains have broken endpoints or are not useful
+EXCLUDED_CHAIN_IDS = {
+    # AlephZero - DNS failures
+    '70255b4d28de0fc4e1a193d7e175ad1ccef431598211c55538f1018651a0344e',
+    # Quartz - DNS failures
+    'cd4d732201ebe5d6b014edda071c4203e16867305332f43c2e25ae6c9a1b7e6f',
+    # InvArch - PAUSED
+    '31a7d8914fb31c249b972f18c115f1e22b4b039abbcb03c73b6774c5642f9efe',
+    # Aleph Zero EVM - PAUSED
+    'eip155:41455',
+}
+
 
 def load_json(path: Path) -> list | dict:
     """Load JSON file."""
@@ -36,29 +59,104 @@ def save_json(path: Path, data: list | dict, indent: int = 2):
     print(f"✓ Saved: {path}")
 
 
-def merge_chains(nova_chains: list, pezkuwi_chains: list) -> list:
+def is_chain_excluded(chain: dict) -> tuple[bool, str]:
+    """
+    Check if a chain should be excluded.
+
+    Returns:
+        (excluded: bool, reason: str)
+    """
+    chain_id = chain.get('chainId', '')
+    name = chain.get('name', '')
+    options = chain.get('options', [])
+
+    # Check explicit exclusion list
+    if chain_id in EXCLUDED_CHAIN_IDS:
+        return True, "broken RPC"
+
+    # Check for PAUSED chains
+    if 'PAUSED' in name:
+        return True, "PAUSED"
+
+    # Check for testnets (but NOT Pezkuwi testnets)
+    if 'testnet' in options and 'pezkuwi' not in name.lower() and 'zagros' not in name.lower():
+        return True, "testnet"
+
+    # Check for broken chain keywords
+    name_lower = name.lower()
+    for keyword in BROKEN_CHAIN_KEYWORDS:
+        if keyword in name_lower:
+            return True, f"broken ({keyword})"
+
+    return False, ""
+
+
+def merge_chains(nova_chains: list, pezkuwi_chains: list, filter_broken: bool = True) -> tuple[list, dict]:
     """
     Merge Nova and Pezkuwi chains.
-    Pezkuwi chains are prepended to appear first in the wallet.
-    Duplicate chainIds are handled (Pezkuwi takes priority).
+
+    Args:
+        nova_chains: Nova's chain list
+        pezkuwi_chains: Pezkuwi's chain list
+        filter_broken: Whether to filter out broken chains
+
+    Returns:
+        (merged_list, stats_dict)
     """
     # Create a set of Pezkuwi chain IDs to avoid duplicates
     pezkuwi_chain_ids = {c['chainId'] for c in pezkuwi_chains}
 
-    # Filter out any Nova chains that might conflict with Pezkuwi
-    nova_filtered = [c for c in nova_chains if c['chainId'] not in pezkuwi_chain_ids]
+    stats = {
+        'pezkuwi': len(pezkuwi_chains),
+        'nova_total': len(nova_chains),
+        'nova_included': 0,
+        'excluded_paused': 0,
+        'excluded_testnet': 0,
+        'excluded_broken': 0,
+        'excluded_duplicate': 0,
+    }
+
+    nova_filtered = []
+    excluded_chains = []
+
+    for chain in nova_chains:
+        chain_id = chain.get('chainId', '')
+
+        # Skip duplicates
+        if chain_id in pezkuwi_chain_ids:
+            stats['excluded_duplicate'] += 1
+            continue
+
+        # Check if should be excluded
+        if filter_broken:
+            excluded, reason = is_chain_excluded(chain)
+            if excluded:
+                excluded_chains.append((chain.get('name', 'Unknown'), reason))
+                if 'PAUSED' in reason:
+                    stats['excluded_paused'] += 1
+                elif 'testnet' in reason:
+                    stats['excluded_testnet'] += 1
+                else:
+                    stats['excluded_broken'] += 1
+                continue
+
+        nova_filtered.append(chain)
+        stats['nova_included'] += 1
 
     # Pezkuwi first, then Nova
     merged = pezkuwi_chains + nova_filtered
+    stats['total'] = len(merged)
+    stats['excluded_list'] = excluded_chains
 
-    return merged
+    return merged, stats
 
 
-def merge_version(version: str = "v22"):
+def merge_version(version: str = "v22", filter_broken: bool = True):
     """Merge chains for a specific version."""
-    print(f"\n{'='*50}")
+    print(f"\n{'='*60}")
     print(f"Merging chains for {version}")
-    print(f"{'='*50}")
+    print(f"Mode: {'FILTERED (exclude broken)' if filter_broken else 'FULL (all chains)'}")
+    print(f"{'='*60}")
 
     # Paths
     nova_chains_path = NOVA_BASE / "chains" / version / "chains.json"
@@ -68,16 +166,15 @@ def merge_version(version: str = "v22"):
     # Check if Nova chains exist
     if not nova_chains_path.exists():
         print(f"⚠ Nova chains not found: {nova_chains_path}")
-        # Try root level chains.json
         nova_chains_path = NOVA_BASE / "chains" / "chains.json"
         if not nova_chains_path.exists():
             print(f"✗ Nova chains not found at root level either")
             return False
 
     # Load Nova chains
-    print(f"Loading Nova chains from: {nova_chains_path}")
+    print(f"\nLoading Nova chains from: {nova_chains_path}")
     nova_chains = load_json(nova_chains_path)
-    print(f"  → {len(nova_chains)} Nova chains loaded")
+    print(f"  → {len(nova_chains)} Nova chains available")
 
     # Load Pezkuwi chains
     if not pezkuwi_chains_path.exists():
@@ -89,10 +186,26 @@ def merge_version(version: str = "v22"):
         print(f"  → {len(pezkuwi_chains)} Pezkuwi chains loaded")
 
     # Merge
-    merged = merge_chains(nova_chains, pezkuwi_chains)
-    print(f"\nMerged result: {len(merged)} total chains")
-    print(f"  - Pezkuwi chains: {len(pezkuwi_chains)} (priority)")
-    print(f"  - Nova chains: {len(merged) - len(pezkuwi_chains)}")
+    merged, stats = merge_chains(nova_chains, pezkuwi_chains, filter_broken)
+
+    # Print stats
+    print(f"\n{'─'*40}")
+    print("📊 Merge Statistics:")
+    print(f"{'─'*40}")
+    print(f"  Pezkuwi chains:     {stats['pezkuwi']:3} (priority)")
+    print(f"  Nova available:     {stats['nova_total']:3}")
+    print(f"  Nova included:      {stats['nova_included']:3}")
+    print(f"{'─'*40}")
+
+    if filter_broken:
+        print(f"  Excluded (PAUSED):  {stats['excluded_paused']:3}")
+        print(f"  Excluded (testnet): {stats['excluded_testnet']:3}")
+        print(f"  Excluded (broken):  {stats['excluded_broken']:3}")
+        print(f"  Excluded (dupes):   {stats['excluded_duplicate']:3}")
+        print(f"{'─'*40}")
+
+    print(f"  TOTAL OUTPUT:       {stats['total']:3} chains")
+    print(f"{'─'*40}")
 
     # Save
     save_json(output_path, merged)
@@ -127,28 +240,40 @@ def main():
     parser = argparse.ArgumentParser(description="Merge Nova and Pezkuwi chain configs")
     parser.add_argument("--version", "-v", default="v22", help="Chain config version (default: v22)")
     parser.add_argument("--update", "-u", action="store_true", help="Update Nova submodule first")
+    parser.add_argument("--full", "-f", action="store_true", help="Include ALL chains (no filtering)")
     parser.add_argument("--all", "-a", action="store_true", help="Merge all versions")
     args = parser.parse_args()
 
-    print("╔══════════════════════════════════════════════════╗")
-    print("║     Pezkuwi Wallet Chain Config Merger           ║")
-    print("╚══════════════════════════════════════════════════╝")
+    print("╔════════════════════════════════════════════════════════════╗")
+    print("║       Pezkuwi Wallet Chain Config Merger                   ║")
+    print("║       Nova Base + Pezkuwi Overlay Architecture             ║")
+    print("╚════════════════════════════════════════════════════════════╝")
 
     # Update Nova if requested
     if args.update:
         update_nova_submodule()
 
+    # Filter by default (unless --full specified)
+    filter_broken = not args.full
+
     # Merge
     if args.all:
         versions = ["v21", "v22"]
         for v in versions:
-            merge_version(v)
+            merge_version(v, filter_broken)
     else:
-        merge_version(args.version)
+        merge_version(args.version, filter_broken)
 
-    print("\n✓ Merge complete!")
-    print("\nPezkuwi chains will appear FIRST in the wallet.")
-    print("Nova ecosystem chains follow after Pezkuwi.")
+    print("\n" + "="*60)
+    print("✓ Merge complete!")
+    print("="*60)
+
+    if filter_broken:
+        print("\n📋 Filtered mode:")
+        print("   - PAUSED chains excluded")
+        print("   - Testnets excluded (except Pezkuwi)")
+        print("   - Broken RPC chains excluded")
+        print("\n💡 To include all 98 Nova chains, run with --full flag")
 
 
 if __name__ == "__main__":