overlay: OBS control window via WebSocket API (#773)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change
Adds an overlay window widget for controlling OBS over WebSocket.

Add new lines to the FPS widget that shows recording / streaming timers.

Show notifications for major state changes (stream started/stopped,
recording started/paused/resumed/stopped)

## Testing

src/spice2x/launcher/launcher.cpp

@@ -102,6 +102,7 @@
 #include "overlay/notifications.h"
 #include "overlay/windows/patch_manager.h"
 #include "overlay/windows/iidx_seg.h"
+#include "overlay/windows/obs.h"
 #include "rawinput/rawinput.h"
 #include "rawinput/touch.h"
 #include "reader/reader.h"
@@ -1437,6 +1438,26 @@ int main_implementation(int argc, char *argv[]) {
         cfg::CONFIGURATOR_FORCE_SOFTWARE_RENDER = true;
     }
 
+    // OBS WebSocket overlay settings
+    if (options[launcher::Options::OBSWebSocketEnabled].value_bool()) {
+        overlay::windows::OBS_CONTROL_ENABLED = true;
+    }
+    if (options[launcher::Options::OBSWebSocketHost].is_active()) {
+        overlay::windows::OBS_CONTROL_HOST = options[launcher::Options::OBSWebSocketHost].value_text();
+    }
+    if (options[launcher::Options::OBSWebSocketPort].is_active()) {
+        const auto obs_port = options[launcher::Options::OBSWebSocketPort].value_uint32();
+        if (obs_port > 0 && obs_port <= 65535) {
+            overlay::windows::OBS_CONTROL_PORT = static_cast<uint16_t>(obs_port);
+        }
+    }
+    if (options[launcher::Options::OBSWebSocketPassword].is_active()) {
+        overlay::windows::OBS_CONTROL_PASSWORD = options[launcher::Options::OBSWebSocketPassword].value_text();
+    }
+    if (options[launcher::Options::OBSWebSocketDebug].value_bool()) {
+        overlay::windows::OBS_CONTROL_DEBUG = true;
+    }
+
     // API debugging
     if (api_debug && !cfg::CONFIGURATOR_STANDALONE) {
         API_CONTROLLER = std::make_unique<api::Controller>(api_port, api_pass, api_pretty);

src/spice2x/launcher/options.cpp

@@ -52,6 +52,7 @@ static const std::vector<std::string> CATEGORY_ORDER_NETWORK = {
 static const std::vector<std::string> CATEGORY_ORDER_OVERLAY = {
     "General Overlay",
     "Game Overlay",
+    "OBS Control",
 };
 
 static const std::vector<std::string> CATEGORY_ORDER_ADVANCED = {
@@ -3201,6 +3202,51 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .type = OptionType::Bool,
         .category = "Development",
     },
+    {
+        // OBSWebSocketEnabled
+        .title = "OBS WebSocket Enable",
+        .name = "obsenable",
+        .desc = "Enables the in-game OBS Control overlay and its connection to the OBS Studio "
+            "obs-websocket (v5) server.",
+        .type = OptionType::Bool,
+        .category = "OBS Control",
+    },
+    {
+        // OBSWebSocketHost
+        .title = "OBS WebSocket Host",
+        .name = "obshost",
+        .desc = "Host name or IP address of the OBS Studio obs-websocket (v5) server used by "
+            "the in-game OBS Control overlay. Defaults to 127.0.0.1 when left empty.",
+        .type = OptionType::Text,
+        .category = "OBS Control",
+    },
+    {
+        // OBSWebSocketPort
+        .title = "OBS WebSocket Port",
+        .name = "obsport",
+        .desc = "Port of the OBS Studio obs-websocket (v5) server. Defaults to 4455 when left empty.",
+        .type = OptionType::Integer,
+        .category = "OBS Control",
+    },
+    {
+        // OBSWebSocketPassword
+        .title = "OBS WebSocket Password",
+        .name = "obspass",
+        .desc = "Password for the OBS Studio obs-websocket (v5) server. Leave empty if "
+            "authentication is disabled in OBS.",
+        .type = OptionType::Text,
+        .category = "OBS Control",
+        .sensitive = true,
+    },
+    {
+        // OBSWebSocketDebug
+        .title = "OBS WebSocket Debug",
+        .name = "obsdebug",
+        .desc = "Writes the OBS WebSocket client's internal connection diagnostics to the log. "
+            "Only enable this when troubleshooting connection problems.",
+        .type = OptionType::Bool,
+        .category = "OBS Control",
+    },
 };
 
 const std::vector<std::string> &launcher::get_categories(Options::OptionsCategory category) {

src/spice2x/launcher/options.h

@@ -305,7 +305,12 @@ namespace launcher {
             DisableHighResTimer,
             EnableICMPHook,
             AutoElevate,
-            CfgForceSoftwareRender
+            CfgForceSoftwareRender,
+            OBSWebSocketEnabled,
+            OBSWebSocketHost,
+            OBSWebSocketPort,
+            OBSWebSocketPassword,
+            OBSWebSocketDebug
         };
 
         enum class OptionsCategory {