feat: the key picker's tabs go under its heading, with help text

The share popup is titled for what's shared; above the search, "Pick
a secret to encrypt with" says the recipient needs read access to it,
with Go to's tabs under it.

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

internal/ui/app/sharefiles.go

@@ -15,6 +15,7 @@ import (
 	"git.kebcloud.no/keb/lazysecrets/internal/provider"
 	"git.kebcloud.no/keb/lazysecrets/internal/ref"
 	"git.kebcloud.no/keb/lazysecrets/internal/share"
+	"git.kebcloud.no/keb/lazysecrets/internal/ui/panes"
 )
 
 // Sharing env files as an encrypted lazysecrets://share link (package
@@ -146,8 +147,9 @@ func (m *Model) pickShareKey(s sharing) tea.Cmd {
 	}
 	m.search.pickTitle = shareTitle(s)
 	m.search.pickLines = append(m.sharedFiles(s), "",
-		"Pick the secret to encrypt them with: whoever can read it can open the link.",
-		m.st.Muted.Render("Its value isn't shown or put in the link. share.key sets a default."))
+		panes.TitleStyle(m.st, true).Render("Pick a secret to encrypt with"),
+		m.st.Muted.Render("The recipient needs read access to it to decrypt the files. Its value isn't"),
+		m.st.Muted.Render("shown or put in the link. share.key sets one for a repo, or for all."))
 	m.fillSearch(false)
 	return tea.Batch(cmd, m.searchLoads())
 }