feat(v2): T-308A window 80% of screen, 2x3 gallery, Esc close, button states

- Window opens at 80% of the primary display (Windows GetSystemMetrics).
- Gallery is now 2 columns x 3 rows and the right panel is narrower.
- Esc closes the full-image viewer (key focus + filter).
- Start/Stop grey out per running state (gtx.Disabled drops input); a hard
  ReportIssue resets running so Start re-enables. Cross-compiles for Windows.

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

v2/internal/ui/screen_other.go

@@ -0,0 +1,6 @@
+//go:build !windows
+
+package ui
+
+// screenSize is unknown off Windows; the caller falls back to the spec size.
+func screenSize() (int, int) { return 0, 0 }

v2/internal/ui/screen_windows.go

@@ -0,0 +1,18 @@
+//go:build windows
+
+package ui
+
+// SM_CXSCREEN / SM_CYSCREEN return the primary display size in pixels.
+const (
+	smCXScreen = 0
+	smCYScreen = 1
+)
+
+var procGetSystemMetrics = user32.NewProc("GetSystemMetrics")
+
+// screenSize returns the primary display size in pixels, or (0, 0) if unavailable.
+func screenSize() (int, int) {
+	width, _, _ := procGetSystemMetrics.Call(uintptr(smCXScreen))
+	height, _, _ := procGetSystemMetrics.Call(uintptr(smCYScreen))
+	return int(width), int(height)
+}

v2/internal/ui/window.go

@@ -12,6 +12,7 @@ import (
 
 	"gioui.org/app"
 	"gioui.org/font/gofont"
+	"gioui.org/io/key"
 	"gioui.org/layout"
 	"gioui.org/op"
 	"gioui.org/op/clip"
@@ -26,7 +27,11 @@ import (
 	"silverpose/v2/internal/monitor"
 )
 
-const galleryCapacity = 9 // 3 columns x 3 rows
+const (
+	galleryColumns  = 2
+	galleryRows     = 3
+	galleryCapacity = galleryColumns * galleryRows // 2 columns x 3 rows
+)
 
 // Light Windows theme tokens (see docs/ui/silver-pose-ui-ux-spec.md).
 var (
@@ -83,6 +88,7 @@ type Window struct {
 	seenAlerts  map[string]struct{}
 	incoming    []galleryIncoming
 	seenEvents  map[string]struct{}
+	running     bool
 
 	// Touched only by the event-loop goroutine.
 	imageOp       paint.ImageOp
@@ -110,10 +116,15 @@ func NewWindow(settings Settings, commands Commands) (*Window, error) {
 	model := NewViewModel()
 	model.SetSourceReady(settings.SourceEnvironment, settings.SourceEnvironment != "")
 
+	width, height := spec.Width, spec.Height
+	if screenWidth, screenHeight := screenSize(); screenWidth > 0 && screenHeight > 0 {
+		width = screenWidth * 80 / 100
+		height = screenHeight * 80 / 100
+	}
 	appWindow := new(app.Window)
 	appWindow.Option(
 		app.Title(spec.Title),
-		app.Size(unit.Dp(spec.Width), unit.Dp(spec.Height)),
+		app.Size(unit.Dp(width), unit.Dp(height)),
 		app.MinSize(unit.Dp(960), unit.Dp(640)),
 	)
 	window := &Window{
@@ -159,12 +170,18 @@ func (window *Window) loop() error {
 }
 
 func (window *Window) start() {
+	window.mu.Lock()
+	window.running = true
+	window.mu.Unlock()
 	if window.commands.Start != nil {
 		window.commands.Start()
 	}
 }
 
 func (window *Window) stop() {
+	window.mu.Lock()
+	window.running = false
+	window.mu.Unlock()
 	if window.commands.Stop != nil {
 		window.commands.Stop()
 	}
@@ -227,6 +244,7 @@ func (window *Window) ReportIssue(message string) {
 	window.model.ConnectionText = "视频流：" + message
 	window.model.Critical = false
 	window.model.StateText = "检测状态：正常"
+	window.running = false
 	window.mu.Unlock()
 	window.appWindow.Invalidate()
 }
@@ -240,6 +258,7 @@ func (window *Window) layout(gtx layout.Context) layout.Dimensions {
 	gen := window.imageGen
 	pending := window.pending
 	incoming := window.incoming
+	running := window.running
 	window.incoming = nil
 	window.mu.Unlock()
 
@@ -269,6 +288,19 @@ func (window *Window) layout(gtx layout.Context) layout.Dimensions {
 	if window.viewerClose.Clicked(gtx) {
 		window.viewing = nil
 	}
+	// Esc closes the full-image viewer.
+	for {
+		event, ok := gtx.Event(key.Filter{Focus: window, Name: key.NameEscape})
+		if !ok {
+			break
+		}
+		if pressed, ok := event.(key.Event); ok && pressed.State == key.Press {
+			window.viewing = nil
+		}
+	}
+	if window.viewing != nil {
+		gtx.Execute(key.FocusCmd{Tag: window})
+	}
 	if window.ackButton.Clicked(gtx) {
 		window.mu.Lock()
 		window.pending = nil
@@ -281,7 +313,7 @@ func (window *Window) layout(gtx layout.Context) layout.Dimensions {
 			layout.Rigid(window.layoutTabs),
 			layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
 				if window.active == 0 {
-					return window.layoutMonitor(gtx, model, hasFrame)
+					return window.layoutMonitor(gtx, model, hasFrame, running)
 				}
 				return window.layoutSettings(gtx, model)
 			}),
@@ -335,9 +367,9 @@ func (window *Window) layoutTabs(gtx layout.Context) layout.Dimensions {
 	return layout.Flex{}.Layout(gtx, children...)
 }
 
-func (window *Window) layoutMonitor(gtx layout.Context, model ViewModel, hasFrame bool) layout.Dimensions {
+func (window *Window) layoutMonitor(gtx layout.Context, model ViewModel, hasFrame, running bool) layout.Dimensions {
 	return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
-		layout.Flexed(3, func(gtx layout.Context) layout.Dimensions {
+		layout.Flexed(7, func(gtx layout.Context) layout.Dimensions {
 			return layout.UniformInset(unit.Dp(8)).Layout(gtx, func(gtx layout.Context) layout.Dimensions {
 				if !hasFrame {
 					return layout.Center.Layout(gtx, material.Body1(window.theme, model.ConnectionText).Layout)
@@ -345,17 +377,17 @@ func (window *Window) layoutMonitor(gtx layout.Context, model ViewModel, hasFram
 				return widget.Image{Src: window.imageOp, Fit: widget.Contain, Position: layout.Center}.Layout(gtx)
 			})
 		}),
-		layout.Flexed(2, func(gtx layout.Context) layout.Dimensions {
+		layout.Flexed(3, func(gtx layout.Context) layout.Dimensions {
-			return window.layoutRightPanel(gtx, model)
+			return window.layoutRightPanel(gtx, model, running)
 		}),
 	)
 }
 
-func (window *Window) layoutRightPanel(gtx layout.Context, model ViewModel) layout.Dimensions {
+func (window *Window) layoutRightPanel(gtx layout.Context, model ViewModel, running bool) layout.Dimensions {
-	if window.startButton.Clicked(gtx) {
+	if !running && window.startButton.Clicked(gtx) {
 		window.start()
 	}
-	if window.stopButton.Clicked(gtx) {
+	if running && window.stopButton.Clicked(gtx) {
 		window.stop()
 	}
 	return layout.UniformInset(unit.Dp(10)).Layout(gtx, func(gtx layout.Context) layout.Dimensions {
@@ -379,11 +411,11 @@ func (window *Window) layoutRightPanel(gtx layout.Context, model ViewModel) layo
 			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
 				return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
 					layout.Rigid(func(gtx layout.Context) layout.Dimensions {
-						return smallButton(gtx, window.theme, &window.startButton, "开始监控")
+						return stateButton(gtx, window.theme, &window.startButton, "开始监控", !running)
 					}),
 					layout.Rigid(layout.Spacer{Width: unit.Dp(8)}.Layout),
 					layout.Rigid(func(gtx layout.Context) layout.Dimensions {
-						return smallButton(gtx, window.theme, &window.stopButton, "停止监控")
+						return stateButton(gtx, window.theme, &window.stopButton, "停止监控", running)
 					}),
 				)
 			}),
@@ -410,20 +442,31 @@ func (window *Window) layoutRightPanel(gtx layout.Context, model ViewModel) layo
 }
 
 func smallButton(gtx layout.Context, theme *material.Theme, click *widget.Clickable, label string) layout.Dimensions {
+	return stateButton(gtx, theme, click, label, true)
+}
+
+// stateButton renders a compact button; when disabled it is greyed and, via
+// gtx.Disabled(), drops pointer input so the click never registers.
+func stateButton(gtx layout.Context, theme *material.Theme, click *widget.Clickable, label string, enabled bool) layout.Dimensions {
 	button := material.Button(theme, click, label)
 	button.Inset = layout.Inset{Top: unit.Dp(4), Bottom: unit.Dp(4), Left: unit.Dp(10), Right: unit.Dp(10)}
 	button.TextSize = unit.Sp(13)
+	if !enabled {
+		button.Background = color.NRGBA{R: 0xCF, G: 0xD8, B: 0xE3, A: 0xFF}
+		button.Color = color.NRGBA{R: 0x94, G: 0xA3, B: 0xB8, A: 0xFF}
+		gtx = gtx.Disabled()
+	}
 	return button.Layout(gtx)
 }
 
 func (window *Window) layoutGallery(gtx layout.Context) layout.Dimensions {
-	rows := make([]layout.FlexChild, 0, 3)
+	rows := make([]layout.FlexChild, 0, galleryRows)
-	for r := 0; r < 3; r++ {
+	for r := 0; r < galleryRows; r++ {
 		r := r
 		rows = append(rows, layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
-			cols := make([]layout.FlexChild, 0, 3)
+			cols := make([]layout.FlexChild, 0, galleryColumns)
-			for c := 0; c < 3; c++ {
+			for c := 0; c < galleryColumns; c++ {
-				index := r*3 + c
+				index := r*galleryColumns + c
 				cols = append(cols, layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
 					if index < len(window.gallery) {
 						return window.layoutCell(gtx, window.gallery[index])