feat: add src/main.cpp

src/main.cpp

@@ -0,0 +1,17 @@
+#include "fusion.hpp"
+#include <iostream>
+
+int main() {
+    const std::int64_t now = 100000;
+    Reading primary{"A", 24.0, now - 100};
+    Reading secondary{"B", 25.5, now - 200};
+    for (int scenario = 0; scenario < 4; ++scenario) {
+        if (scenario == 1) secondary.timestamp_ms = now - 9000;
+        if (scenario == 2) { secondary.timestamp_ms = now; secondary.celsius = 37.0; }
+        if (scenario == 3) { primary.celsius = 150.0; secondary.celsius = 150.0; }
+        auto result = fuse(assess_channel(primary, now), assess_channel(secondary, now));
+        std::cout << state_name(result.state) << " source=" << result.source;
+        if (result.celsius) std::cout << " value=" << *result.celsius;
+        std::cout << '\n';
+    }
+}