rebase: bump on-screen version strings 0.5.4 → 0.6.0

Both occurrences in src/oled.cpp (Status header + boot splash) and
the matching README ASCII mockup. Matches our new upstream base.

README.md

@@ -188,7 +188,7 @@ Connection state, paired DualSense BD address, battery % with bar (`+` charging
 
 ```
 ┌──────────────────────────────┐
-│ DS5 Bridge v0.5.4         ●  │
+│ DS5 Bridge v0.6.0         ●  │
 │ 14:3A:9A:FF:D9:F9            │
 │ 87%+ ╔══════════════╗        │
 │      ║██████░░░░░░░░║▌       │

src/oled.cpp

@@ -437,7 +437,7 @@ __attribute__((noinline)) void render_screen() {
 
     const bool connected = bt_is_connected();
 
-    draw_text(0, 0, "DS5 Bridge v0.5.4");
+    draw_text(0, 0, "DS5 Bridge v0.6.0");
     draw_icon(120, 0, connected ? kIconLinkOn : kIconLinkOff, 8, 8);
 
     if (connected) {
@@ -1157,7 +1157,7 @@ void boot_splash() {
         return (128 - (n * 6 - 1)) / 2;
     };
     const char* l1 = "DS5 Bridge";
-    const char* l2 = "v0.5.4";
+    const char* l2 = "v0.6.0";
     const char* l3 = "Pico2W + OLED";
     draw_text(cx_for(l1), 16, l1);
     draw_text(cx_for(l2), 30, l2);