Convert HHmm to Fallout game-hour float

Add parsing and application of HHmm time strings as Fallout game-hour floats so GUI time presets apply correctly. Introduce ParseHHmmToGameHour in plugin/src/F4TWorldStateSync.cpp and use it when building the console command (formats as set gamehour to <float> with fallback to the raw HHmm string if parsing fails). Improve logging to indicate when a parsed HHmm was used. Update protocol/server-world-state.md, changelog.md, and docs/dev-log.md to document the behavior and rationale.

plugin/src/F4TWorldStateSync.cpp

@@ -195,6 +195,47 @@ namespace
 		return value;
 	}
 
+	std::optional<float> ParseHHmmToGameHour(std::string_view a_hhmm)
+	{
+		if (a_hhmm.empty() || a_hhmm.size() > 4) {
+			return std::nullopt;
+		}
+
+		std::string digits;
+		digits.reserve(4);
+		for (const auto ch : a_hhmm) {
+			if (ch < '0' || ch > '9') {
+				return std::nullopt;
+			}
+			digits.push_back(ch);
+		}
+
+		while (digits.size() < 4) {
+			digits.insert(digits.begin(), '0');
+		}
+
+		int hours = 0;
+		int minutes = 0;
+		{
+			const auto* begin = digits.data();
+			const auto* split = begin + 2;
+			const auto* end = begin + 4;
+
+			const auto hourResult = std::from_chars(begin, split, hours);
+			const auto minuteResult = std::from_chars(split, end, minutes);
+			if (hourResult.ec != std::errc{} || hourResult.ptr != split ||
+				minuteResult.ec != std::errc{} || minuteResult.ptr != end) {
+				return std::nullopt;
+			}
+		}
+
+		if (hours < 0 || hours > 23 || minutes < 0 || minutes > 59) {
+			return std::nullopt;
+		}
+
+		return static_cast<float>(hours) + static_cast<float>(minutes) / 60.0F;
+	}
+
 	bool ForceHostWorldStateBroadcast(std::optional<std::uint32_t> a_forcedWeatherFormId, bool a_sendTime)
 	{
 		if (!F4T::WorldStateSync::IsWorldStateHost() || !F4T::Networking::IsConnectedToServer()) {
@@ -394,7 +435,10 @@ namespace
 	void ApplyServerWorldState(const F4T::WorldStateSync::PendingServerWorldState& a_state)
 	{
 		if (a_state.timeHHmm && !a_state.timeHHmm->empty()) {
-			const auto command = std::format("set gamehour to {}", *a_state.timeHHmm);
+			const auto parsedGameHour = ParseHHmmToGameHour(*a_state.timeHHmm);
+			const auto command = parsedGameHour
+				? std::format("set gamehour to {:.4f}", *parsedGameHour)
+				: std::format("set gamehour to {}", *a_state.timeHHmm);
 			RE::Console::ExecuteCommand(command.c_str());
 
 			float gameHour = 0.0F;
@@ -415,7 +459,14 @@ namespace
 			}
 
 			if (ShouldLog("server_world_state_time_apply")) {
-				LogInfo(std::format("Applied server time command: {}", command));
+				if (parsedGameHour) {
+					LogInfo(std::format(
+						"Applied server time command: {} (from HHmm={}).",
+						command,
+						*a_state.timeHHmm));
+				} else {
+					LogInfo(std::format("Applied server time command: {}", command));
+				}
 			}
 		}