refactor(core): drop header if title unset

diff --git a/core/embed/rust/src/ui/api/firmware_micropython.rs b/core/embed/rust/src/ui/api/firmware_micropython.rs
index 8fe667ef..6c30bc26 100644
--- a/core/embed/rust/src/ui/api/firmware_micropython.rs
+++ b/core/embed/rust/src/ui/api/firmware_micropython.rs
@@ -1274,7 +1274,7 @@ extern "C" fn new_show_wait_text(message: Obj) -> Obj {
 
 extern "C" fn new_show_warning(n_args: usize, args: *const Obj, kwargs: *mut Map) -> Obj {
     let block = move |_args: &[Obj], kwargs: &Map| {
-        let title: TString = kwargs.get(Qstr::MP_QSTR_title)?.try_into()?;
+        let title: Option<TString> = kwargs.get(Qstr::MP_QSTR_title)?.try_into_option()?;
         let button: TString = kwargs.get(Qstr::MP_QSTR_button)?.try_into()?;
         let value: TString = kwargs.get_or(Qstr::MP_QSTR_value, "".into())?;
         let description: TString = kwargs.get_or(Qstr::MP_QSTR_description, "".into())?;
@@ -2155,7 +2155,7 @@ pub static mp_module_trezorui_api: Module = obj_module! {
 
     /// def show_warning(
     ///     *,
-    ///     title: str,
+    ///     title: str | None,
     ///     button: str,
     ///     value: str = "",
     ///     description: str = "",
diff --git a/core/embed/rust/src/ui/layout_bolt/ui_firmware.rs b/core/embed/rust/src/ui/layout_bolt/ui_firmware.rs
index 3f554687..3bf2b78e 100644
--- a/core/embed/rust/src/ui/layout_bolt/ui_firmware.rs
+++ b/core/embed/rust/src/ui/layout_bolt/ui_firmware.rs
@@ -1271,7 +1271,7 @@ impl FirmwareUI for UIBolt {
     }
 
     fn show_warning(
-        title: TString<'static>,
+        title: Option<TString<'static>>,
         button: TString<'static>,
         value: TString<'static>,
         description: TString<'static>,
@@ -1286,7 +1286,7 @@ impl FirmwareUI for UIBolt {
             theme::BG,
         );
         new_show_modal(
-            title,
+            title.unwrap_or(TString::empty()),
             value,
             description,
             (!button.is_empty()).then_some(button),
diff --git a/core/embed/rust/src/ui/layout_caesar/ui_firmware.rs b/core/embed/rust/src/ui/layout_caesar/ui_firmware.rs
index cb624e65..de882e2b 100644
--- a/core/embed/rust/src/ui/layout_caesar/ui_firmware.rs
+++ b/core/embed/rust/src/ui/layout_caesar/ui_firmware.rs
@@ -1366,7 +1366,7 @@ impl FirmwareUI for UICaesar {
     }
 
     fn show_warning(
-        _title: TString<'static>,
+        _title: Option<TString<'static>>,
         button: TString<'static>,
         value: TString<'static>,
         description: TString<'static>,
diff --git a/core/embed/rust/src/ui/layout_delizia/ui_firmware.rs b/core/embed/rust/src/ui/layout_delizia/ui_firmware.rs
index d4acf9d8..058fa9eb 100644
--- a/core/embed/rust/src/ui/layout_delizia/ui_firmware.rs
+++ b/core/embed/rust/src/ui/layout_delizia/ui_firmware.rs
@@ -1233,7 +1233,7 @@ impl FirmwareUI for UIDelizia {
     }
 
     fn show_warning(
-        title: TString<'static>,
+        title: Option<TString<'static>>,
         button: TString<'static>,
         value: TString<'static>,
         description: TString<'static>,
@@ -1253,20 +1253,23 @@ impl FirmwareUI for UIDelizia {
             .into_paragraphs(),
         );
 
-        let frame = if title.is_empty() {
-            if danger {
-                // Disallow showing "dangerous" warning with no header.
-                return Err(Error::ValueError(c"Non-empty title is required"));
+        let frame = match title {
+            None => {
+                if danger {
+                    // Disallow showing "dangerous" warning with no header.
+                    return Err(Error::ValueError(c"Non-empty title is required"));
+                }
+                Frame::content(content)
+            }
+            Some(title) => {
+                let header = Header::left_aligned(title);
+                let header = if danger {
+                    header.with_danger_icon()
+                } else {
+                    header.with_warning_low_icon()
+                };
+                Frame::with_header(header, content)
             }
-            Frame::content(content)
-        } else {
-            let header = Header::left_aligned(title);
-            let header = if danger {
-                header.with_danger_icon()
-            } else {
-                header.with_warning_low_icon()
-            };
-            Frame::with_header(header, content)
         };
         let frame = if danger {
             frame.with_tap_footer(action)
diff --git a/core/embed/rust/src/ui/layout_eckhart/ui_firmware.rs b/core/embed/rust/src/ui/layout_eckhart/ui_firmware.rs
index c4b58be6..0252b100 100644
--- a/core/embed/rust/src/ui/layout_eckhart/ui_firmware.rs
+++ b/core/embed/rust/src/ui/layout_eckhart/ui_firmware.rs
@@ -1546,7 +1546,7 @@ impl FirmwareUI for UIEckhart {
     }
 
     fn show_warning(
-        title: TString<'static>,
+        title: Option<TString<'static>>,
         button: TString<'static>,
         value: TString<'static>,
         description: TString<'static>,
@@ -1575,14 +1575,13 @@ impl FirmwareUI for UIEckhart {
             ActionBar::new_single(Button::with_text(button))
         };
         let screen = TextScreen::new(paragraphs).with_action_bar(action_bar);
-        let screen = if title.is_empty() {
-            screen
-        } else {
-            screen.with_header(
+        let screen = match title {
+            None => screen,
+            Some(title) => screen.with_header(
                 Header::new(title)
                     .with_icon(theme::ICON_INFO, color)
                     .with_text_style(style),
-            )
+            ),
         };
         let layout = LayoutObj::new(screen)?;
         Ok(layout)
diff --git a/core/embed/rust/src/ui/ui_firmware.rs b/core/embed/rust/src/ui/ui_firmware.rs
index 56f65467..c48bb160 100644
--- a/core/embed/rust/src/ui/ui_firmware.rs
+++ b/core/embed/rust/src/ui/ui_firmware.rs
@@ -464,7 +464,7 @@ pub trait FirmwareUI {
     fn show_wait_text(text: TString<'static>) -> Result<impl LayoutMaybeTrace, Error>;
 
     fn show_warning(
-        title: TString<'static>,
+        title: Option<TString<'static>>,
         button: TString<'static>,
         value: TString<'static>,
         description: TString<'static>,
diff --git a/core/mocks/generated/trezorui_api.pyi b/core/mocks/generated/trezorui_api.pyi
index 7ae02f53..90f2ae54 100644
--- a/core/mocks/generated/trezorui_api.pyi
+++ b/core/mocks/generated/trezorui_api.pyi
@@ -834,7 +834,7 @@ def show_wait_text(message: str, /) -> LayoutObj[None]:
 # rust/src/ui/api/firmware_micropython.rs
 def show_warning(
     *,
-    title: str,
+    title: str | None,
     button: str,
     value: str = "",
     description: str = "",