Introduce a Big Picture mode and support building two app targets. CMakeLists was refactored to add a helper (add_nebula_app_target) and now registers NebulaBrowser and NebulaBigPicture executables, moving UI/assets post-build copying into the helper. A new app/main_bigpicture.cpp entry was added and RunNebula now accepts LaunchOptions (AppMode) with a new LaunchOptions struct. NebulaController was extended heavily to manage a BigPicture browser role: creation, enter/exit mode, layout logic, cursor injection/removal, remote input handlers (mouse move/click/wheel/text), and state syncing. Cef/browser_client updated for the new BigPicture role and message filtering. Platform API gained MoveCursorToBrowserPoint with platform stubs/Win implementation. Big-picture UI files (CSS/JS/HTML) were also updated to support the new mode.
Call CloseBrowser(true) for chrome, popup and tab browsers to force shutdown. Immediately destroy the top-level window and call MaybeFinishShutdown() to avoid hangs when WM_CLOSE is not resent by Alloy child-window paths. Route "close" and new "exit-bigpicture" chrome commands through OnWindowCloseRequested so they trigger the same shutdown flow. Add IsBigPictureFrame and permit the "exit-bigpicture" process message from bigpicture internal frames.
Track menu popup visibility and propagate zoom level to the popup. Add menu_popup_visible_ flag, SendMenuPopupZoom(), and call it when creating/showing the popup and when adjusting zoom. Make CreateNewTab accept an optional URL and route popup/new-tab flows to it. Prevent per-tab child closes from triggering app shutdown by tracking closing_tab_browsers_ and adding ForgetClosingTabBrowser(). Treat MenuPopup role specially when enabling frame hit-testing.
Platform: remove usage of ApplyRoundedBrowserRegion and switch menu popup sizing to use resized client_size helpers (consolidate calculations across Win/Mac/Linux). UI: update menu-popup CSS/JS (new styling, font, zoom formatting API via NebulaMenuPopup.setZoomLevel), wire settings to use nebulaNative.postMessage for new-tab, and remove the static menu-popup.html. Misc: small chrome CSS/JS tweaks and ensure chrome state includes zoomLevel.
Add persistent site history storage and plumbing between the renderer settings UI and the native app. The app now loads/saves site_history.txt in the user data directory (max 200 entries, http/https-only, stored one URL per line) and records visited sites on navigation. Settings pages receive the history via injected JavaScript when the settings page finishes loading, and a "clear-site-history" message from the settings UI clears the on-disk history and updates the renderer.
Other changes: allow settings-related process messages from content frames in the CEF client, introduce OnContentLoadFinished to trigger history injection, expose electronAPI.send/sendToHost (and reuse the native postMessage handler) in the V8 context, and remove the BigPicture in-app history UI/refresh/clear handlers (history is now managed by the native app). Also cleaned up includes and added helper utilities for JSON escaping, lowercasing, and file path handling. The initial tab restore logic was simplified to always create an initial tab (home or initial_url) and persist the session.
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.
Introduce core application structure and browser management: add NebulaController and run entry (src/app/*) to centralize window, tab and CEF lifecycle logic; implement TabManager and NebulaTab (src/browser/*) for tab creation, navigation and state tracking; add URL utilities (NormalizeNavigationInput, JsonEscape) and CEF browser client glue (src/cef/browser_client.cpp/.h) to forward chrome commands and content events. Update app/main.cpp to delegate startup to nebula::app::RunNebula. Add UI assets (chrome.html, chrome.css, chrome.js, lucide, menu-popup updates) and remove obsolete nebot.html. Update CMakeLists to include new sources, add ${CMAKE_SOURCE_DIR}/src to includes and link dwmapi on Windows. Overall this refactors startup and splits responsibilities for cleaner tab and browser lifecycle handling.