Support nebula:// internal pages & GPU tools

Introduce support for an internal nebula:// URL scheme and internal page routing (ResolveInternalUrl / ToInternalUrl), including dedicated slugs for home, settings, downloads, big-picture, gpu-diagnostics, insecure and a 404 fallback. Wire internal resolution into browser creation and tab navigation so internal pages load from local UI files. Add an insecure-warning interstitial flow with a navigate-insecure command and a one-shot bypass set (ShouldBypassInsecureWarning) so content can request navigating to an HTTP target after user confirmation. Harden BrowserClient handling to resolve Chromium new-tab and nebula internal URLs, redirect HTTP to the insecure warning when appropriate, and handle 404 responses by loading the internal 404 page. Update chrome UI behavior to hide internal home URLs, accept nebula:// in navigation input checks, and add a GPU Diagnostics page (revamped UI + diagnostic scripts) plus menu entry. Misc: improve URL utilities (scheme checks, percent-encoding, decorations), fix 404 display text, adjust menu popup size, tweak window frame styling (DWM attributes) and remove branding block from chrome UI CSS.

src/app/nebula_controller.cpp

@@ -55,7 +55,7 @@ RECT MenuPopupRect(HWND hwnd, const nebula::window::BrowserLayout& layout) {
     GetClientRect(hwnd, &client);
 
     const int width = ScaleForWindow(hwnd, 260);
-    const int height = ScaleForWindow(hwnd, 218);
+    const int height = ScaleForWindow(hwnd, 258);
     const int margin = ScaleForWindow(hwnd, 12);
     const int overlap = ScaleForWindow(hwnd, 2);
 
@@ -103,6 +103,10 @@ std::string WithCacheBuster(std::string url) {
     return url + separator + "nebula_cache_bust=" + std::to_string(GetTickCount64()) + fragment;
 }
 
+std::string GetChromeDisplayUrl(const std::string& url) {
+    return nebula::ui::IsInternalHomeUrl(url) ? std::string{} : url;
+}
+
 void SetBrowserVisible(CefRefPtr<CefBrowser> browser, bool visible) {
     if (!browser) {
         return;
@@ -209,6 +213,12 @@ void NebulaController::OnBrowserClosing(nebula::cef::BrowserRole role, CefRefPtr
 void NebulaController::OnChromeCommand(const std::string& command, const std::string& payload) {
     if (command == "navigate") {
         tabs_.LoadURL(payload);
+    } else if (command == "navigate-insecure") {
+        const std::string target = nebula::browser::NormalizeNavigationInput(payload);
+        if (nebula::ui::IsHttpUrl(target)) {
+            insecure_warning_bypasses_.insert(target);
+            tabs_.LoadURL(target);
+        }
     } else if (command == "new-tab") {
         CreateNewTab();
     } else if (command == "activate-tab") {
@@ -233,6 +243,9 @@ void NebulaController::OnChromeCommand(const std::string& command, const std::st
     } else if (command == "big-picture") {
         CloseMenuPopup();
         tabs_.LoadURL(nebula::ui::GetBigPictureUrl());
+    } else if (command == "gpu-diagnostics") {
+        CloseMenuPopup();
+        tabs_.LoadURL(nebula::ui::GetGpuDiagnosticsUrl());
     } else if (command == "toggle-devtools") {
         ToggleDevTools();
     } else if (command == "zoom-out") {
@@ -263,7 +276,10 @@ void NebulaController::OnChromeCommand(const std::string& command, const std::st
 }
 
 void NebulaController::OnContentAddressChanged(CefRefPtr<CefBrowser> browser, const std::string& url) {
-    tabs_.UpdateURL(browser, nebula::ui::IsChromiumNewTabUrl(url) ? nebula::ui::GetHomeUrl() : url);
+    tabs_.UpdateURL(browser,
+                    nebula::ui::IsChromiumNewTabUrl(url)
+                        ? nebula::ui::GetHomeUrl()
+                        : nebula::ui::ToInternalUrl(url));
 }
 
 void NebulaController::OnContentTitleChanged(CefRefPtr<CefBrowser> browser, const std::string& title) {
@@ -296,6 +312,20 @@ void NebulaController::OnPopupRequested(CefRefPtr<CefBrowser> browser, const std
                       : target_url);
 }
 
+bool NebulaController::ShouldBypassInsecureWarning(CefRefPtr<CefBrowser> browser, const std::string& target_url) {
+    if (!tabs_.OwnsBrowser(browser)) {
+        return false;
+    }
+
+    const auto bypass = insecure_warning_bypasses_.find(target_url);
+    if (bypass == insecure_warning_bypasses_.end()) {
+        return false;
+    }
+
+    insecure_warning_bypasses_.erase(bypass);
+    return true;
+}
+
 void NebulaController::CreateNewTab() {
     if (auto* tab = tabs_.ActiveTab()) {
         SetBrowserVisible(tab->browser, false);
@@ -376,7 +406,8 @@ void NebulaController::CreateContentBrowser() {
     CefBrowserSettings browser_settings;
     content_client_ = new nebula::cef::NebulaBrowserClient(nebula::cef::BrowserRole::Content, this);
     CefWindowInfo window_info = ChildWindowInfo(window_->hwnd(), layout.content);
-    CefBrowserHost::CreateBrowser(window_info, content_client_, url, browser_settings, nullptr, nullptr);
+    CefBrowserHost::CreateBrowser(
+        window_info, content_client_, nebula::ui::ResolveInternalUrl(url), browser_settings, nullptr, nullptr);
 }
 
 void NebulaController::ToggleMenuPopup() {
@@ -476,6 +507,7 @@ void NebulaController::SendChromeState(const nebula::browser::NebulaTab& tab) {
         return;
     }
 
+    const std::string display_url = GetChromeDisplayUrl(tab.url);
     std::string tabs_json = "[";
     const auto& tabs = tabs_.Tabs();
     for (size_t i = 0; i < tabs.size(); ++i) {
@@ -495,7 +527,7 @@ void NebulaController::SendChromeState(const nebula::browser::NebulaTab& tab) {
     const std::string script =
         "window.NebulaChrome && window.NebulaChrome.applyState({"
         "\"id\":" + std::to_string(tab.id) +
-        ",\"url\":\"" + nebula::browser::JsonEscape(tab.url) + "\""
+        ",\"url\":\"" + nebula::browser::JsonEscape(display_url) + "\""
         ",\"title\":\"" + nebula::browser::JsonEscape(tab.title) + "\""
         ",\"isLoading\":" + std::string(tab.is_loading ? "true" : "false") +
         ",\"progress\":" + std::to_string(tab.load_progress) +

src/app/nebula_controller.h

@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <string>
+#include <unordered_set>
 #include <vector>
 
 #include "browser/tab_manager.h"
@@ -34,6 +35,7 @@ public:
     void OnContentLoadProgressChanged(CefRefPtr<CefBrowser> browser, double progress) override;
     void OnContentFaviconChanged(CefRefPtr<CefBrowser> browser, const std::vector<std::string>& urls) override;
     void OnPopupRequested(CefRefPtr<CefBrowser> browser, const std::string& target_url) override;
+    bool ShouldBypassInsecureWarning(CefRefPtr<CefBrowser> browser, const std::string& target_url) override;
 
 private:
     void CreateNewTab();
@@ -65,6 +67,7 @@ private:
     CefRefPtr<nebula::cef::NebulaBrowserClient> chrome_client_;
     CefRefPtr<nebula::cef::NebulaBrowserClient> content_client_;
     CefRefPtr<nebula::cef::NebulaBrowserClient> menu_popup_client_;
+    std::unordered_set<std::string> insecure_warning_bypasses_;
 };
 
 }  // namespace nebula::app