fix: a demo repo's SOPS value can be the share key

The demo provider finds repos by their remote, as the repo provider
does, so a key in a demo repo's SOPS file can be read. Opening a
share link uses the repo's clone only when it's on disk (the demo's
aren't), else asks where to save. The demo GitHub client secret is 40
characters, like real ones, so it passes share.keyRules.

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

internal/ui/app/sharefiles_test.go

@@ -1,6 +1,7 @@
 package app
 
 import (
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -203,10 +204,19 @@ func TestShareInDemo(t *testing.T) {
 	if !strings.HasPrefix(clip.content, "lazysecrets://share/") {
 		t.Fatalf("copied %q (%s)", clip.content, d.m.flash.text)
 	}
+	link := clip.content
+	// A value in a demo repo's SOPS file can be the key too, found by
+	// the repo's remote.
+	clip.content = ""
+	d.run(d.m.shareFiles(src, nil))
+	d.send(tea.PasteMsg{Content: "lazysecrets://repo/" + url.PathEscape(src.Detail) + "/config%2Foauth.enc.json/github.client_secret"})
+	if !strings.HasPrefix(clip.content, "lazysecrets://share/") {
+		t.Errorf("with the demo repo's key: copied %q (%s)", clip.content, d.m.flash.text)
+	}
 
 	dir, _ := filepath.EvalSymlinks(t.TempDir())
 	d.m.placeDir = dir
-	d.send(tea.PasteMsg{Content: clip.content})
+	d.send(tea.PasteMsg{Content: link})
 	d.keys("o")
 	if d.m.prompt == nil || d.m.prompt.input == nil || !strings.Contains(d.screen(), "isn't among your repos") {
 		t.Fatalf("doesn't ask where:\n%s", d.screen())