feat(benchmarks): add noise injection experiment support to CAM retrieval benchmark

- Remove hard assertion blocking WRITE_NOISE_EN=1 in retrieval benchmark tests
- Add conditional exact_match assertion: enforces 100% when noise=off, skips when noise=on
- New script run_retrieval_noise_sweep.py: sweeps noise 0–100% (step 10%) and produces markdown summary
- Add just recipes: cam-benchmark-retrieval-sweep, cam-benchmark-sweep-cifar10, cam-benchmark-sweep-cifar100
- Add rsync-based remote sync commands for outputs and docs

hw/sim/benchmarks/retrieval/test_retrieval_benchmark.py

@@ -288,8 +288,6 @@ async def cam_retrieval_benchmark(dut):
     write_noise_rate_den = int(get_param(dut, "WRITE_NOISE_RATE_DEN", 100) or 100)
     mode = mode_from_params(write_noise_en)
 
-    if write_noise_en:
-        raise AssertionError("First retrieval benchmark version only supports WRITE_NOISE_EN=0")
     if num_rows % lanes != 0:
         raise AssertionError("Retrieval benchmark requires NUM_ROWS divisible by LANES")
 
@@ -355,4 +353,13 @@ async def cam_retrieval_benchmark(dut):
             str(out_dir.relative_to(_project_root())),
         )
 
-    assert result["metrics"]["5"]["exact_match_rate"] == 1.0
+    if write_noise_en == 0:
+        assert result["metrics"]["5"]["exact_match_rate"] == 1.0, (
+            f"Expected perfect exact match with no noise, got "
+            f"{result['metrics']['5']['exact_match_rate']}"
+        )
+    else:
+        dut._log.info(
+            "Noise enabled (WRITE_NOISE_RATE=%d/%d) — exact_match assertion skipped",
+            write_noise_rate_num, write_noise_rate_den,
+        )