chore: remove configuration files and enhance blockchain explorer with advanced search, analytics, and export features

- Delete .aitbc.yaml.example CLI configuration template
- Delete .lycheeignore link checker exclusion rules
- Delete .nvmrc Node.js version specification
- Add advanced search panel with filters for address, amount range, transaction type, time range, and validator
- Add analytics dashboard with transaction volume, active addresses, and block time metrics
- Add Chart.js integration

dev/scripts/patch_poa2.py

@@ -0,0 +1,50 @@
+with open("/home/oib/windsurf/aitbc/apps/blockchain-node/src/aitbc_chain/consensus/poa.py", "r") as f:
+    content = f.read()
+
+# Add CircuitBreaker class if missing, or import it if needed. It seems it was removed during our patching or wasn't there.
+# Let's check if it exists in the original or another file. Ah, the test expects it in `aitbc_chain.consensus.poa`.
+import re
+has_cb = "class CircuitBreaker" in content
+
+if not has_cb:
+    cb_code = """
+import time
+
+class CircuitBreaker:
+    def __init__(self, threshold: int, timeout: int):
+        self._threshold = threshold
+        self._timeout = timeout
+        self._failures = 0
+        self._last_failure_time = 0.0
+        self._state = "closed"
+
+    @property
+    def state(self) -> str:
+        if self._state == "open":
+            if time.time() - self._last_failure_time > self._timeout:
+                self._state = "half-open"
+        return self._state
+
+    def allow_request(self) -> bool:
+        state = self.state
+        if state == "closed":
+            return True
+        if state == "half-open":
+            return True
+        return False
+
+    def record_failure(self) -> None:
+        self._failures += 1
+        self._last_failure_time = time.time()
+        if self._failures >= self._threshold:
+            self._state = "open"
+
+    def record_success(self) -> None:
+        self._failures = 0
+        self._state = "closed"
+"""
+    # Insert it before PoAProposer
+    content = content.replace("class PoAProposer:", cb_code + "\nclass PoAProposer:")
+    
+with open("/home/oib/windsurf/aitbc/apps/blockchain-node/src/aitbc_chain/consensus/poa.py", "w") as f:
+    f.write(content)