Added three new ASV benchmark suites for the core module:

1. core_circuit_breaker_bench.py - Benchmarks for CircuitBreaker class:
   - Closed state call overhead
   - Open state fast-fail latency
   - State transition overhead (closed→open, open→half-open, half-open→closed)
   - Async operations
   - Initialization overhead

2. core_retry_patterns_bench.py - Benchmarks for retry decorators:
   - Decorator construction overhead for exponential backoff, jitter, timeout, and result-based retry
   - Happy-path invocation overhead
   - Async decorator operations
   - Decorator usage with function arguments
   - Factory function performance
   - Various configuration scenarios

3. core_retry_service_patterns_bench.py - Benchmarks for service-level retry:
   - retry_service_operation decorator construction and invocation
   - retry_auto_debug decorator performance
   - RetryContext operations
   - is_read_only_plan_operation utility
   - Different wait strategies (exponential, linear, fixed, jitter)

These benchmarks ensure latency regressions in core resilience primitives are caught early.

ISSUES CLOSED: #1921

@@ -0,0 +7,4 @@
+from __future__ import annotations
+
+import asyncio
+import time

@@ -0,0 +121,4 @@
+            try:
+                breaker.call(lambda: 1 / 0)
+            except ZeroDivisionError:
+                pass

@@ -0,0 +6,4 @@
+
+from __future__ import annotations
+
+import asyncio

@@ -0,0 +6,4 @@
+
+from __future__ import annotations
+
+import asyncio

@@ -0,0 +55,4 @@
+    def time_failure_count_check(self) -> None:
+        """Benchmark failure count property access."""
+        _ = self.breaker.failure_count
+

@@ -0,0 +247,4 @@
+        """Benchmark default initialization."""
+        CircuitBreaker()
+
+    def time_custom_initialization(self) -> None: