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/bitflags-1.3.2/tests/compile-fail/non_integer_base/all_defined.rs

@@ -0,0 +1,123 @@
+use std::{
+    fmt::{
+        self,
+        Debug,
+        Display,
+        LowerHex,
+        UpperHex,
+        Octal,
+        Binary,
+    },
+    ops::{
+        BitAnd,
+        BitOr,
+        BitXor,
+        BitAndAssign,
+        BitOrAssign,
+        BitXorAssign,
+        Not,
+    },
+};
+
+use bitflags::bitflags;
+
+// Ideally we'd actually want this to work, but currently need something like `num`'s `Zero`
+// With some design work it could be made possible
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+struct MyInt(u8);
+
+impl BitAnd for MyInt {
+    type Output = Self;
+
+    fn bitand(self, other: Self) -> Self {
+        MyInt(self.0 & other.0)
+    }
+}
+
+impl BitOr for MyInt {
+    type Output = Self;
+
+    fn bitor(self, other: Self) -> Self {
+        MyInt(self.0 | other.0)
+    }
+}
+
+impl BitXor for MyInt {
+    type Output = Self;
+
+    fn bitxor(self, other: Self) -> Self {
+        MyInt(self.0 ^ other.0)
+    }
+}
+
+impl BitAndAssign for MyInt {
+    fn bitand_assign(&mut self, other: Self) {
+        self.0 &= other.0
+    }
+}
+
+impl BitOrAssign for MyInt {
+    fn bitor_assign(&mut self, other: Self) {
+        self.0 |= other.0
+    }
+}
+
+impl BitXorAssign for MyInt {
+    fn bitxor_assign(&mut self, other: Self) {
+        self.0 ^= other.0
+    }
+}
+
+impl Debug for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.0, f)
+    }
+}
+
+impl Display for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.0, f)
+    }
+}
+
+impl LowerHex for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        LowerHex::fmt(&self.0, f)
+    }
+}
+
+impl UpperHex for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        UpperHex::fmt(&self.0, f)
+    }
+}
+
+impl Octal for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Octal::fmt(&self.0, f)
+    }
+}
+
+impl Binary for MyInt {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Binary::fmt(&self.0, f)
+    }
+}
+
+impl Not for MyInt {
+    type Output = MyInt;
+
+    fn not(self) -> Self {
+        MyInt(!self.0)
+    }
+}
+
+bitflags! {
+    struct Flags128: MyInt {
+        const A = MyInt(0b0000_0001u8);
+        const B = MyInt(0b0000_0010u8);
+        const C = MyInt(0b0000_0100u8);
+    }
+}
+
+fn main() {}

vendor/bitflags-1.3.2/tests/compile-fail/non_integer_base/all_defined.stderr.beta

@@ -0,0 +1,27 @@
+error[E0308]: mismatched types
+   --> $DIR/all_defined.rs:115:1
+    |
+115 | / bitflags! {
+116 | |     struct Flags128: MyInt {
+117 | |         const A = MyInt(0b0000_0001u8);
+118 | |         const B = MyInt(0b0000_0010u8);
+119 | |         const C = MyInt(0b0000_0100u8);
+120 | |     }
+121 | | }
+    | |_^ expected struct `MyInt`, found integer
+    |
+    = note: this error originates in the macro `__impl_all_bitflags` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0308]: mismatched types
+   --> $DIR/all_defined.rs:115:1
+    |
+115 | / bitflags! {
+116 | |     struct Flags128: MyInt {
+117 | |         const A = MyInt(0b0000_0001u8);
+118 | |         const B = MyInt(0b0000_0010u8);
+119 | |         const C = MyInt(0b0000_0100u8);
+120 | |     }
+121 | | }
+    | |_^ expected struct `MyInt`, found integer
+    |
+    = note: this error originates in the macro `__impl_bitflags` (in Nightly builds, run with -Z macro-backtrace for more info)

vendor/bitflags-1.3.2/tests/compile-fail/non_integer_base/all_missing.rs

@@ -0,0 +1,13 @@
+use bitflags::bitflags;
+
+struct MyInt(u8);
+
+bitflags! {
+    struct Flags128: MyInt {
+        const A = MyInt(0b0000_0001);
+        const B = MyInt(0b0000_0010);
+        const C = MyInt(0b0000_0100);
+    }
+}
+
+fn main() {}

vendor/bitflags-1.3.2/tests/compile-fail/non_integer_base/all_missing.stderr.beta

@@ -0,0 +1,13 @@
+error[E0204]: the trait `Copy` may not be implemented for this type
+  --> $DIR/all_missing.rs:5:1
+   |
+5  | / bitflags! {
+6  | |     struct Flags128: MyInt {
+7  | |         const A = MyInt(0b0000_0001);
+8  | |         const B = MyInt(0b0000_0010);
+9  | |         const C = MyInt(0b0000_0100);
+10 | |     }
+11 | | }
+   | |_^ this field does not implement `Copy`
+   |
+   = note: this error originates in the derive macro `Copy` (in Nightly builds, run with -Z macro-backtrace for more info)