fix: resolve explorer transaction search, timestamp formatting, and optimize RPC total_count queries

apps/blockchain-explorer/main.py

@@ -418,6 +418,34 @@ async def api_block(height: int):
     return await get_block(height)
 
 
+
+@app.get("/api/transactions/{tx_hash}")
+async def api_transaction(tx_hash: str):
+    """API endpoint for transaction data, normalized for frontend"""
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get(f"{BLOCKCHAIN_RPC_URL}/tx/{tx_hash}")
+            if response.status_code == 200:
+                tx = response.json()
+                # Normalize for frontend expectations
+                payload = tx.get("payload", {})
+                return {
+                    "hash": tx.get("tx_hash"),
+                    "block_height": tx.get("block_height"),
+                    "from": tx.get("sender"),
+                    "to": tx.get("recipient"),
+                    "type": payload.get("type", "transfer"),
+                    "amount": payload.get("amount", 0),
+                    "fee": payload.get("fee", 0),
+                    "timestamp": tx.get("created_at")
+                }
+            elif response.status_code == 404:
+                raise HTTPException(status_code=404, detail="Transaction not found")
+        except httpx.RequestError as e:
+            print(f"Error fetching transaction: {e}")
+    raise HTTPException(status_code=500, detail="Internal server error")
+
+
 @app.get("/health")
 async def health():
     """Health check endpoint"""

apps/blockchain-node/src/aitbc_chain/rpc/router.py

@@ -1,4 +1,5 @@
 from __future__ import annotations
+from sqlalchemy import func
 
 import asyncio
 import json
@@ -200,8 +201,9 @@ async def get_transactions(limit: int = 20, offset: int = 0) -> Dict[str, Any]:
             .limit(limit)
         ).all()
         
-        # Get total count for pagination info
-        total_count = len(session.exec(select(Transaction)).all())
+# Get total count for pagination info using optimized SQL count
+        total_count = session.exec(select(func.count()).select_from(Transaction)).one()
+
         
         if not transactions:
             metrics_registry.increment("rpc_get_transactions_empty_total")
@@ -350,8 +352,8 @@ async def get_address_details(address: str, limit: int = 20, offset: int = 0) ->
         ).all()
         
         # Get total counts
-        total_sent = len(session.exec(select(Transaction).where(Transaction.sender == address)).all())
-        total_received = len(session.exec(select(Transaction).where(Transaction.recipient == address)).all())
+        total_sent = session.exec(select(func.count()).select_from(Transaction).where(Transaction.sender == address)).one()
+        total_received = session.exec(select(func.count()).select_from(Transaction).where(Transaction.recipient == address)).one()
         
         # Serialize transactions
         serialize_tx = lambda tx: {
@@ -419,8 +421,8 @@ async def get_addresses(limit: int = 20, offset: int = 0, min_balance: int = 0)
         address_list = []
         for addr in addresses:
             # Get transaction counts
-            sent_count = len(session.exec(select(Transaction).where(Transaction.sender == addr.address)).all())
-            received_count = len(session.exec(select(Transaction).where(Transaction.recipient == addr.address)).all())
+            sent_count = session.exec(select(func.count()).select_from(Transaction).where(Transaction.sender == addr.address)).one()
+            received_count = session.exec(select(func.count()).select_from(Transaction).where(Transaction.recipient == addr.address)).one()
             
             address_list.append({
                 "address": addr.address,