feat(msgviewer): wire image extraction and composite rendering into PartViewer

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/msgviewer.go

@@ -439,7 +439,10 @@ type PartViewer struct {
 	width      int
 	height     int
 
-	links []string
+	links      []string
+	imageRefs  []parse.ImageRef     // extracted image references from filter output
+	composite  *compositeContent    // composite renderer (non-nil when images present)
+	scroll     int                  // scroll offset for composite mode
 }
 
 const copying int32 = 1
@@ -611,37 +614,56 @@ func (pv *PartViewer) attemptCopy() {
 		pv.source = parse.StripAnsi(pv.hyperlinks(pv.source))
 	}
 	if pv.filter != pv.pager {
-		// Filter is a separate process that needs to output to the pager.
 		pv.filter.Stdin = pv.source
-		pv.filter.Stdout = pv.pagerin
+		var filterBuf bytes.Buffer
+		pv.filter.Stdout = &filterBuf
 		pv.filter.Stderr = pv.pagerin
 		err := pv.filter.Start()
 		if err != nil {
 			log.Errorf("error running filter: %v", err)
 			return
 		}
-	}
-	go func() {
-		defer log.PanicHandler()
-		defer atomic.StoreInt32(&pv.copying, 0)
-		var err error
-		if pv.filter == pv.pager {
-			// Filter already implements its own paging.
-			_, err = io.Copy(pv.pagerin, pv.source)
-			if err != nil {
-				log.Errorf("io.Copy: %s", err)
-			}
-		} else {
-			err = pv.filter.Wait()
+		go func() {
+			defer log.PanicHandler()
+			defer atomic.StoreInt32(&pv.copying, 0)
+			err := pv.filter.Wait()
 			if err != nil {
 				log.Errorf("filter.Wait: %v", err)
 			}
-		}
-		err = pv.pagerin.Close()
-		if err != nil {
-			log.Errorf("error closing pager pipe: %v", err)
-		}
-	}()
+			// Extract image markers from filter output
+			cleaned, images := parse.ExtractImages(&filterBuf)
+			if len(images) > 0 {
+				pv.imageRefs = images
+				cleanedBytes, _ := io.ReadAll(cleaned)
+				pv.composite = newCompositeContent(
+					string(cleanedBytes), images, 80)
+				pv.Invalidate()
+			} else {
+				// No images — forward to pager as normal
+				_, copyErr := io.Copy(pv.pagerin, cleaned)
+				if copyErr != nil {
+					log.Errorf("io.Copy: %s", copyErr)
+				}
+			}
+			err = pv.pagerin.Close()
+			if err != nil {
+				log.Errorf("error closing pager pipe: %v", err)
+			}
+		}()
+	} else {
+		go func() {
+			defer log.PanicHandler()
+			defer atomic.StoreInt32(&pv.copying, 0)
+			_, err := io.Copy(pv.pagerin, pv.source)
+			if err != nil {
+				log.Errorf("io.Copy: %s", err)
+			}
+			err = pv.pagerin.Close()
+			if err != nil {
+				log.Errorf("error closing pager pipe: %v", err)
+			}
+		}()
+	}
 }
 
 func (pv *PartViewer) writeMailHeaders() {
@@ -816,6 +838,13 @@ func (pv *PartViewer) Draw(ctx *ui.Context) {
 	if pv.term != nil {
 		pv.term.Draw(ctx)
 	}
+	// Composite mode: text + images from filter output
+	if pv.composite != nil {
+		pv.composite.width = ctx.Width()
+		ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', pv.uiConfig.GetStyle(config.STYLE_DEFAULT))
+		pv.composite.Draw(ctx, pv.scroll)
+		return
+	}
 	if pv.image != nil && (pv.resized(ctx) || pv.graphic == nil) {
 		// This path should only occur on resizes or the first pass
 		// after the image is downloaded and could be slow due to
@@ -847,6 +876,10 @@ func (pv *PartViewer) Cleanup() {
 	if pv.graphic != nil {
 		pv.graphic.Destroy()
 	}
+	if pv.composite != nil {
+		pv.composite.Destroy()
+		pv.composite.CleanupFiles()
+	}
 }
 
 func (pv *PartViewer) resized(ctx *ui.Context) bool {