fix: Configure WebSocket endpoint from environment variables

## Problem
Frontend was showing 'connecting network' message on production (pezkuwichain.io) because:
1. WebSocket endpoint was hardcoded to localhost in App.tsx
2. DEFAULT_ENDPOINT in polkadot.ts was not reading environment variables

## Solution

### shared/blockchain/polkadot.ts
- Added getWebSocketEndpoint() function to read VITE_NETWORK and corresponding VITE_WS_ENDPOINT_* env vars
- Changed DEFAULT_ENDPOINT from hardcoded value to call getWebSocketEndpoint()
- Now correctly uses wss://ws.pezkuwichain.io in production

### web/src/App.tsx
- Removed hardcoded endpoint="ws://127.0.0.1:9944" prop from PolkadotProvider
- Now uses DEFAULT_ENDPOINT which reads from environment

### web/vite.config.ts
- Minor formatting improvements (no functional changes)

### CLAUDE_README_KRITIK.md (New file)
- Critical documentation for future Claude instances
- Documents VPS validator setup, bootnode configuration
- Strict warnings not to modify working blockchain
- Troubleshooting commands and procedures
- Frontend deployment steps

## Result
- Production site now correctly connects to wss://ws.pezkuwichain.io
- Environment-based configuration working as expected
- Local dev still uses ws://127.0.0.1:9944

## Files Changed
- shared/blockchain/polkadot.ts: Dynamic endpoint selection
- web/src/App.tsx: Remove hardcoded endpoint
- CLAUDE_README_KRITIK.md: Critical documentation (new)

shared/blockchain/polkadot.ts

@@ -17,15 +17,32 @@ export const PEZKUWI_NETWORK: BlockchainNetwork = {
  * Common blockchain endpoints
  */
 export const BLOCKCHAIN_ENDPOINTS = {
-  mainnet: 'wss://pezkuwichain.app:9944',
-  beta: 'wss://beta-rpc.pezkuwi.art',
+  mainnet: 'wss://mainnet.pezkuwichain.io',
+  testnet: 'wss://ws.pezkuwichain.io',
   local: 'ws://127.0.0.1:9944',
 } as const;
 
 /**
- * Default endpoint (currently using beta testnet)
+ * Get the appropriate WebSocket endpoint based on environment
  */
-export const DEFAULT_ENDPOINT = BLOCKCHAIN_ENDPOINTS.beta;
+function getWebSocketEndpoint(): string {
+  const network = import.meta.env.VITE_NETWORK || 'local';
+
+  switch (network) {
+    case 'mainnet':
+      return import.meta.env.VITE_WS_ENDPOINT_MAINNET || BLOCKCHAIN_ENDPOINTS.mainnet;
+    case 'testnet':
+      return import.meta.env.VITE_WS_ENDPOINT_TESTNET || BLOCKCHAIN_ENDPOINTS.testnet;
+    case 'local':
+    default:
+      return import.meta.env.VITE_WS_ENDPOINT_LOCAL || BLOCKCHAIN_ENDPOINTS.local;
+  }
+}
+
+/**
+ * Default endpoint (reads from environment variables)
+ */
+export const DEFAULT_ENDPOINT = getWebSocketEndpoint();
 
 /**
  * Get block explorer URL for a transaction