app: add code for macOS and Windows apps under 'app' (#12933)

* app: add code for macOS and Windows apps under 'app'

* app: add readme

* app: windows and linux only for now

* ci: fix ui CI validation

---------

Co-authored-by: jmorganca <jmorganca@gmail.com>

app/dialog/dlgs_darwin.go

@@ -0,0 +1,82 @@
+package dialog
+
+import (
+	"github.com/ollama/ollama/app/dialog/cocoa"
+)
+
+func (b *MsgBuilder) yesNo() bool {
+	return cocoa.YesNoDlg(b.Msg, b.Dlg.Title)
+}
+
+func (b *MsgBuilder) info() {
+	cocoa.InfoDlg(b.Msg, b.Dlg.Title)
+}
+
+func (b *MsgBuilder) error() {
+	cocoa.ErrorDlg(b.Msg, b.Dlg.Title)
+}
+
+func (b *FileBuilder) load() (string, error) {
+	return b.run(false)
+}
+
+func (b *FileBuilder) loadMultiple() ([]string, error) {
+	return b.runMultiple()
+}
+
+func (b *FileBuilder) save() (string, error) {
+	return b.run(true)
+}
+
+func (b *FileBuilder) run(save bool) (string, error) {
+	star := false
+	var exts []string
+	for _, filt := range b.Filters {
+		for _, ext := range filt.Extensions {
+			if ext == "*" {
+				star = true
+			} else {
+				exts = append(exts, ext)
+			}
+		}
+	}
+	if star && save {
+		/* OSX doesn't allow the user to switch visible file types/extensions. Also
+		** NSSavePanel's allowsOtherFileTypes property has no effect for an open
+		** dialog, so if "*" is a possible extension we must always show all files. */
+		exts = nil
+	}
+	f, err := cocoa.FileDlg(save, b.Dlg.Title, exts, star, b.StartDir, b.StartFile, b.ShowHiddenFiles)
+	if f == "" && err == nil {
+		return "", ErrCancelled
+	}
+	return f, err
+}
+
+func (b *FileBuilder) runMultiple() ([]string, error) {
+	star := false
+	var exts []string
+	for _, filt := range b.Filters {
+		for _, ext := range filt.Extensions {
+			if ext == "*" {
+				star = true
+			} else {
+				exts = append(exts, ext)
+			}
+		}
+	}
+
+	files, err := cocoa.MultiFileDlg(b.Dlg.Title, exts, star, b.StartDir, b.ShowHiddenFiles)
+	if len(files) == 0 && err == nil {
+		return nil, ErrCancelled
+	}
+	return files, err
+}
+
+func (b *DirectoryBuilder) browse() (string, error) {
+	f, err := cocoa.DirDlg(b.Dlg.Title, b.StartDir, b.ShowHiddenFiles)
+	if f == "" && err == nil {
+		return "", ErrCancelled
+	}
+	return f, err
+}