feat: pick the share key in Go to, or by reference

Sharing without share.key opens Go to as a picker of secrets instead
of asking for a link: it lists only secrets, enter picks one, and a
pasted reference picks it too. The key, there and in share.key or
--key, can be a secret's lazysecrets:// link, Key Vault URL or
@Microsoft.KeyVault(...) reference.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/ui/app/sharefiles_test.go

@@ -18,9 +18,6 @@ import (
 // which take about a second on purpose.
 const scryptWait = 20 * time.Second
 
-// shareKeyLink is a demo secret, long enough to be a key.
-const shareKeyLink = "lazysecrets://azure/" + kv + "/secrets/db-password"
-
 // cloneWith makes a clone of git.example.com/team/app holding files.
 func cloneWith(t *testing.T, files map[string]string) string {
 	t.Helper()
@@ -35,7 +32,7 @@ func cloneWith(t *testing.T, files map[string]string) string {
 
 // shareFrom shares a repo's env files from lazysecrets started in it,
 // returning the link copied.
-func shareFrom(t *testing.T, root string) string {
+func shareFrom(t *testing.T, root string, paste bool) string {
 	t.Helper()
 	clip := &fakeClipboard{}
 	d := newDriverOpts(t, Options{Clipboard: clip}, fake.Azure(0), repo.New(repo.Settings{Dir: root}))
@@ -44,12 +41,32 @@ func shareFrom(t *testing.T, root string) string {
 		t.Fatalf("selected %v, want the repo", src.ID)
 	}
 	d.keys("S", "f")
-	// No share.key set: it asks which secret.
-	if d.m.prompt == nil || d.m.prompt.input == nil {
-		t.Fatalf("no key prompt: %s", d.m.flash.text)
+	// No share.key set: it asks which secret, in Go to, which lists
+	// only secrets.
+	v := d.m.search
+	if v == nil || v.pick == nil {
+		t.Fatalf("no secret picker: %s", d.m.flash.text)
+	}
+	if paste {
+		// A reference pasted is picked as it is.
+		d.send(tea.PasteMsg{Content: "https://" + kv + "/secrets/db-password"})
+	} else {
+		for _, r := range "app-prod db-password" {
+			d.keys(string(r))
+		}
+		if len(v.shown) == 0 {
+			t.Fatalf("no secrets to pick:\n%s", d.screen())
+		}
+		for _, o := range v.shown {
+			if _, ok := pickable(o); !ok {
+				t.Errorf("not a secret: %s", o.label)
+			}
+		}
+		if !strings.Contains(d.screen(), "Encrypt with which secret?") {
+			t.Errorf("not titled as a picker:\n%s", d.screen())
+		}
+		d.keys("enter")
 	}
-	d.send(tea.PasteMsg{Content: shareKeyLink})
-	d.keys("enter")
 	if !strings.Contains(d.screen(), ".env") || !strings.Contains(d.screen(), "db-password") {
 		t.Errorf("the files and key aren't shown before sharing:\n%s", d.screen())
 	}
@@ -67,7 +84,7 @@ func TestShareFilesRoundTrip(t *testing.T) {
 	link := shareFrom(t, cloneWith(t, map[string]string{
 		".env":     "DB_PASSWORD=hunter2\n",
 		"prod.env": "TOKEN=abc\n",
-	}))
+	}), false)
 
 	// A colleague's clone: .env is there already, prod.env isn't.
 	theirs := cloneWith(t, map[string]string{".env": "DB_PASSWORD=old\n"})
@@ -104,7 +121,7 @@ func TestShareLinkElsewhereAsksWhere(t *testing.T) {
 	if _, err := exec.LookPath("git"); err != nil {
 		t.Skip("no git")
 	}
-	link := shareFrom(t, cloneWith(t, map[string]string{".env": "A=1\n"}))
+	link := shareFrom(t, cloneWith(t, map[string]string{".env": "A=1\n"}), true)
 	dir, _ := filepath.EvalSymlinks(t.TempDir())
 	d := newDriverOpts(t, Options{Dir: dir}, fake.Azure(0))
 	d.wait = scryptWait