feat(app): implement basic function

General
- 配置界面支持配置对象存储桶
- 快捷键进入截图
- 一键上传截图 & 复制截图链接

MacOS
- 状态栏指示器和应用图标

internal/infrastructure/tray/tray.go

@@ -0,0 +1,84 @@
+// Package tray runs the menu-bar agent UI for SnapGo on macOS / Linux /
+// Windows. It is intentionally decoupled from the main App struct: the App
+// supplies a small set of callbacks (Capture / Settings / Quit) so that this
+// package never imports the application service stack.
+//
+// We use fyne.io/systray (a fork of getlantern/systray) because it is
+// designed to coexist with other GUI runloops — important when the host
+// process is also driving a Wails / Cocoa main loop.
+package tray
+
+import (
+	"fyne.io/systray"
+)
+
+// Callbacks bundles the menu actions the host application wants to expose.
+// Splitting these into a struct (rather than 3 positional arguments) keeps
+// future extension cheap — we can add e.g. OnCheckForUpdates without
+// touching the call sites.
+type Callbacks struct {
+	OnCapture  func()
+	OnSettings func()
+	OnQuit     func()
+}
+
+// Start installs the menu-bar status item and returns immediately. The
+// fyne.io/systray fork exposes RunWithExternalLoop precisely for cases like
+// ours where the host process already owns the main thread (Wails).
+//
+// The returned `stop` function tears down the status item; call it from the
+// host's shutdown path.
+func Start(cbs Callbacks) (start, stop func()) {
+	onReady := func() {
+		systray.SetTemplateIcon(templateIconBytes, regularIconBytes)
+		systray.SetTooltip("SnapGo")
+
+		mCapture := systray.AddMenuItem("Capture screenshot", "Take a region screenshot")
+		mSettings := systray.AddMenuItem("Settings…", "Open settings window")
+		systray.AddSeparator()
+		mQuit := systray.AddMenuItem("Quit SnapGo", "Quit the application")
+
+		// Pump menu clicks on a dedicated goroutine. Channel sends from
+		// systray are non-blocking, so a slow user callback does not back
+		// up the UI thread.
+		go func() {
+			for {
+				select {
+				case <-mCapture.ClickedCh:
+					if cbs.OnCapture != nil {
+						cbs.OnCapture()
+					}
+				case <-mSettings.ClickedCh:
+					if cbs.OnSettings != nil {
+						cbs.OnSettings()
+					}
+				case <-mQuit.ClickedCh:
+					if cbs.OnQuit != nil {
+						cbs.OnQuit()
+					}
+					systray.Quit()
+					return
+				}
+			}
+		}()
+	}
+
+	onExit := func() { /* nothing to clean up */ }
+
+	// RunWithExternalLoop registers the status item without blocking the
+	// caller — the returned `start` should be invoked once the host's
+	// runloop is up so the icon appears. fyne.io/systray returns a
+	// (start, end) pair; we delegate `end` to systray.Quit for symmetry.
+	rawStart, _ := systray.RunWithExternalLoop(onReady, onExit)
+
+	// IMPORTANT: on macOS, `nativeStart` ends up calling
+	//   [NSStatusBar systemStatusBar] -> [-NSStatusBar _statusItemWithLength:...]
+	// which constructs an NSWindow. Cocoa hard-asserts that NSWindow can
+	// only be instantiated on the main thread. Wails v2 invokes OnStartup
+	// from a worker goroutine, so calling rawStart() directly from there
+	// crashes with NSInternalInconsistencyException. We wrap it in
+	// dispatchOnMain so the call is forwarded to the main dispatch queue.
+	start = func() { dispatchOnMain(rawStart) }
+	stop = systray.Quit
+	return start, stop
+}