Add the protocol-comparison module

protocol-comparison/src/main/java/com/ankurm/protocols/QuoteSource.java

@@ -0,0 +1,22 @@
+package com.ankurm.protocols;
+
+import java.time.Instant;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * Deterministic quote generation, shared by all three protocol adapters.
+ *
+ * <p>Deliberately cheap and deliberately allocation-free apart from the record: a benchmark of
+ * three transports must not spend its time in the thing behind them.
+ */
+@Component
+public class QuoteSource {
+
+    public Quote at(String symbol, long seq) {
+        double base = 100.0 + (seq % 97) * 0.01;
+        Instant now = Instant.now();
+        return new Quote(symbol, seq, base, base + 0.02,
+                now.getEpochSecond() * 1_000_000L + now.getNano() / 1_000L);
+    }
+}