chore(copy): standardize metadata formatting and descriptions

- Replace middle dots (·) and em-dashes (—) with pipes (|) and standard punctuation in page titles, descriptions, and image alt texts.
- Shorten the homepage description to be more concise and direct.
- Update file share description phrasing for better readability, changing "click to preview" to "Open to preview" and capitalizing "Expires".

backend/libs/handlers/download.go

@@ -141,7 +141,7 @@ func (a *App) DownloadPage(w http.ResponseWriter, r *http.Request) {
 
 	expiresLabel := boxExpiryLabel(box.ExpiresAt, "Jan 2, 2006 15:04 MST")
 	title := "Shared files on Warpbox"
-	description := fmt.Sprintf("%d file%s shared via Warpbox · expires %s", len(box.Files), plural(len(box.Files)), expiresLabel)
+	description := fmt.Sprintf("%d file%s shared via Warpbox | Expires %s.", len(box.Files), plural(len(box.Files)), expiresLabel)
 	ogImage := absoluteURL(r, fmt.Sprintf("/d/%s/og-image.jpg", box.ID))
 	imageAlt := fmt.Sprintf("%d shared file%s on Warp Box", len(box.Files), plural(len(box.Files)))
 	imageType := "image/jpeg"
@@ -203,7 +203,7 @@ func fileShareDescription(size, contentType string, expiresAt time.Time) string
 	if strings.TrimSpace(contentType) == "" {
 		contentType = "file"
 	}
-	return fmt.Sprintf("%s · %s · click to preview or download · expires %s", size, contentType, boxExpiryLabel(expiresAt, "Jan 2, 2006"))
+	return fmt.Sprintf("%s %s. Open to preview or download. Expires %s.", size, contentType, boxExpiryLabel(expiresAt, "Jan 2, 2006"))
 }
 
 func socialImageURL(r *http.Request, box services.Box, file services.File, view fileView) string {