feat: add display UI with splash screen, dashboard, and RSSI sparkline

Implement full SSD1306 OLED display support:
- Splash screen on boot (1.5s) with project name, version, board
- Dashboard showing radio state, config, counters, RSSI/SNR
- RSSI history sparkline (64-sample ring buffer, 2px-wide bars)
- DisplayOn/DisplayOff host commands routed via dedicated channel
- Pure render functions against generic DrawTarget (no hardware coupling)
- Display on/off control bypasses radio task entirely

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

vendor/pin-project-lite/tests/ui/pin_project/invalid-bounds.rs

@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Generics1<T: 'static : Sized> { //~ ERROR no rules expected the token `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics2<T: 'static : ?Sized> { //~ ERROR no rules expected the token `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics6<T: ?Sized : Sized> { //~ ERROR no rules expected the token `Sized`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause1<T>
+    where
+        T: 'static : Sized //~ ERROR no rules expected the token `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause2<T>
+    where
+        T: 'static : ?Sized //~ ERROR no rules expected the token `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause3<T>
+    where
+        T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause4<T>
+    where
+        T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause5<T>
+    where
+        T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause6<T>
+    where
+        T: ?Sized : Sized //~ ERROR no rules expected the token `Sized`
+    {
+        field: T,
+    }
+}
+
+fn main() {}