Persist ImGui panel layout to disk; quiet audio set_audio_ring log spam

Layout persistence: re-enable io.IniFilename (was nullptr "for the spike"),
anchored to a coop_layout.ini next to the exe so window positions/sizes survive
restarts even when Steam launches us under the donor appid (CWD is unreliable).
Path is UTF-8 for ImGui's file IO. When a saved layout is restored at startup,
suppress the computed-default force so it does not clobber the user's positions;
Reset layout (and a fresh install with no .ini) still applies the default.

Log spam: the worker thread re-attaches every audio ring every tick (idempotent),
and set_audio_ring logged unconditionally, flooding the log. Only log when the
ring pointer actually changes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

host/src/imgui_layer.cpp

@@ -1,12 +1,34 @@
 #include "imgui_layer.hpp"
 
+#include <string>
+
 #include <imgui.h>
 #include <imgui_impl_dx11.h>
 #include <imgui_impl_win32.h>
 
+#include "coop/tool_paths.hpp"
+#include "ui/app_chrome.hpp"
+
 namespace coop
 {
 
+namespace
+{
+// ImGui's file IO treats IniFilename as UTF-8 (it converts to wide for _wfopen), so
+// the path must be UTF-8 rather than the system ANSI code page.
+std::string to_utf8(const std::wstring& w)
+{
+	if (w.empty())
+	{
+		return {};
+	}
+	const int n = WideCharToMultiByte(CP_UTF8, 0, w.c_str(), static_cast<int>(w.size()), nullptr, 0, nullptr, nullptr);
+	std::string s(static_cast<std::size_t>(n), '\0');
+	WideCharToMultiByte(CP_UTF8, 0, w.c_str(), static_cast<int>(w.size()), s.data(), n, nullptr, nullptr);
+	return s;
+}
+} // namespace
+
 ImGuiLayer::~ImGuiLayer()
 {
 	if (initialized_)
@@ -23,7 +45,15 @@ bool ImGuiLayer::init(HWND hwnd, ID3D11Device* device, ID3D11DeviceContext* cont
 	IMGUI_CHECKVERSION();
 	ImGui::CreateContext();
 	ImGuiIO& io = ImGui::GetIO();
-	io.IniFilename = nullptr; // don't litter the cwd with imgui.ini during the spike
+	// Persist the panel layout next to the executable so window positions/sizes survive
+	// restarts. CWD is unreliable when Steam launches us under the donor appid, so anchor
+	// to the exe directory. If a layout already exists, tell the chrome not to force the
+	// computed default on startup (which would clobber the restored positions).
+	const std::wstring ini_w = exe_directory() + L"coop_layout.ini";
+	const bool had_layout = GetFileAttributesW(ini_w.c_str()) != INVALID_FILE_ATTRIBUTES;
+	ini_path_ = to_utf8(ini_w);
+	io.IniFilename = ini_path_.c_str();
+	set_layout_persisted(had_layout);
 	ImGui::StyleColorsDark();
 
 	if (!ImGui_ImplWin32_Init(hwnd))

host/src/imgui_layer.hpp

@@ -1,6 +1,8 @@
 // Owns ImGui setup/teardown for the Win32 + DX11 backends.
 #pragma once
 
+#include <string>
+
 #include <d3d11.h>
 #include <windows.h>
 
@@ -22,6 +24,9 @@ public:
 
 private:
 	bool initialized_ = false;
+	// Backing storage for io.IniFilename (ImGui keeps the pointer, not a copy), so the
+	// layout .ini path must outlive the context. Empty until init() sets it.
+	std::string ini_path_;
 };
 
 } // namespace coop

host/src/ui/app_chrome.cpp

@@ -17,6 +17,9 @@ bool g_layout_reset = false;
 // WorkSize isn't trustworthy on frame 0, and FirstUseEver would otherwise lock in
 // those wrong positions (overlapping) until the user pressed Reset layout.
 int g_startup_force = 4;
+// True when ImGui loaded a saved layout (.ini) at startup; then the startup force is
+// suppressed so the restored window positions survive (Reset layout still re-applies).
+bool g_had_persisted_layout = false;
 } // namespace
 
 void request_layout_reset()
@@ -24,6 +27,11 @@ void request_layout_reset()
 	g_layout_reset = true;
 }
 
+void set_layout_persisted(bool had_persisted_layout)
+{
+	g_had_persisted_layout = had_persisted_layout;
+}
+
 void apply_layout_end_frame()
 {
 	g_layout_reset = false;
@@ -87,7 +95,11 @@ void apply_panel_layout(Panel panel)
 		break;
 	}
 
-	const ImGuiCond cond = (g_layout_reset || g_startup_force > 0) ? ImGuiCond_Always : ImGuiCond_FirstUseEver;
+	// Force the computed layout only when the user asks (Reset layout) or on a fresh
+	// install with no saved layout to restore. Otherwise FirstUseEver lets ImGui's
+	// restored .ini positions stand (and still seeds any brand-new panel).
+	const bool force = g_layout_reset || (!g_had_persisted_layout && g_startup_force > 0);
+	const ImGuiCond cond = force ? ImGuiCond_Always : ImGuiCond_FirstUseEver;
 	ImGui::SetNextWindowPos(pos, cond);
 	ImGui::SetNextWindowSize(size, cond);
 }

host/src/ui/app_chrome.hpp

@@ -43,6 +43,11 @@ void apply_panel_layout(Panel panel);
 void request_layout_reset();
 void apply_layout_end_frame();
 
+// Tell the layout whether ImGui restored a saved layout (.ini) at startup. When it
+// did, the computed default layout must NOT be force-applied on launch (that would
+// clobber the user's saved window positions); only an explicit Reset layout re-applies.
+void set_layout_persisted(bool had_persisted_layout);
+
 // Rolling frame-timing over a ~1 s window, recomputed each window so the status
 // bar can show a stable FPS plus the min/max frame time (jitter) underneath it.
 class FrameStats