feat(core): use "Initiate connection" bootloader label on T2T1, T3B1, T3T1

Replaces the outdated "INSTALL FIRMWARE" / "INSTALL FW" button label on
the bootloader intro screen with one that accurately describes what the
button does — initiating the USB/host connection.

T3W1 (Safe 7) already used "Initiate connection"; this aligns all other
Core devices with that wording. T3B1 (Safe 3) uses a shortened "Init
connection" to fit the 128×64 pixel display.

Closes #6824

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

core/embed/rust/src/ui/layout_bolt/bootloader/intro.rs

@@ -42,7 +42,7 @@ impl<'a> Intro<'a> {
             menu: Button::with_icon(Icon::new(MENU32))
                 .styled(button_bld_menu())
                 .with_expanded_touch_area(Insets::uniform(13)),
-            host: Button::with_text("INSTALL FIRMWARE".into()).styled(button_bld()),
+            host: Button::with_text("INITIATE CONNECTION".into()).styled(button_bld()),
             text: Label::left_aligned(content, TEXT_NORMAL).vertically_centered(),
             warn: (!fw_ok).then_some(
                 Label::new("FIRMWARE CORRUPTED".into(), Alignment::Start, TEXT_WARNING)

core/embed/rust/src/ui/layout_caesar/bootloader/intro.rs

@@ -17,7 +17,7 @@ use super::super::{
     },
 };
 
-const LEFT_BUTTON_TEXT: &str = "INSTALL FW";
+const LEFT_BUTTON_TEXT: &str = "Init connection";
 const RIGHT_BUTTON_TEXT: &str = "MENU";
 
 #[repr(u32)]

core/embed/rust/src/ui/layout_delizia/bootloader/intro.rs

@@ -45,7 +45,7 @@ impl<'a> Intro<'a> {
                     .with_expanded_touch_area(Insets::uniform(13)),
             ),
             host: Child::new(
-                Button::with_text("INSTALL FIRMWARE".into())
+                Button::with_text("INITIATE CONNECTION".into())
                     .styled(button_bld())
                     .with_text_align(Alignment::Center),
             ),