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/nrf52811-pac/src/spis0/status.rs

@@ -0,0 +1,200 @@
+#[doc = "Register `STATUS` reader"]
+pub struct R(crate::R<STATUS_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<STATUS_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<STATUS_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<STATUS_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Register `STATUS` writer"]
+pub struct W(crate::W<STATUS_SPEC>);
+impl core::ops::Deref for W {
+    type Target = crate::W<STATUS_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl core::ops::DerefMut for W {
+    #[inline(always)]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+impl From<crate::W<STATUS_SPEC>> for W {
+    #[inline(always)]
+    fn from(writer: crate::W<STATUS_SPEC>) -> Self {
+        W(writer)
+    }
+}
+#[doc = "Field `OVERREAD` reader - TX buffer over-read detected, and prevented"]
+pub type OVERREAD_R = crate::BitReader<OVERREAD_A>;
+#[doc = "TX buffer over-read detected, and prevented\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum OVERREAD_A {
+    #[doc = "0: Read: error not present"]
+    NOT_PRESENT = 0,
+    #[doc = "1: Read: error present"]
+    PRESENT = 1,
+}
+impl From<OVERREAD_A> for bool {
+    #[inline(always)]
+    fn from(variant: OVERREAD_A) -> Self {
+        variant as u8 != 0
+    }
+}
+impl OVERREAD_R {
+    #[doc = "Get enumerated values variant"]
+    #[inline(always)]
+    pub fn variant(&self) -> OVERREAD_A {
+        match self.bits {
+            false => OVERREAD_A::NOT_PRESENT,
+            true => OVERREAD_A::PRESENT,
+        }
+    }
+    #[doc = "Checks if the value of the field is `NOT_PRESENT`"]
+    #[inline(always)]
+    pub fn is_not_present(&self) -> bool {
+        *self == OVERREAD_A::NOT_PRESENT
+    }
+    #[doc = "Checks if the value of the field is `PRESENT`"]
+    #[inline(always)]
+    pub fn is_present(&self) -> bool {
+        *self == OVERREAD_A::PRESENT
+    }
+}
+#[doc = "TX buffer over-read detected, and prevented\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum OVERREAD_AW {
+    #[doc = "1: Write: clear error on writing '1'"]
+    CLEAR = 1,
+}
+impl From<OVERREAD_AW> for bool {
+    #[inline(always)]
+    fn from(variant: OVERREAD_AW) -> Self {
+        variant as u8 != 0
+    }
+}
+#[doc = "Field `OVERREAD` writer - TX buffer over-read detected, and prevented"]
+pub type OVERREAD_W<'a, const O: u8> = crate::BitWriter<'a, u32, STATUS_SPEC, OVERREAD_AW, O>;
+impl<'a, const O: u8> OVERREAD_W<'a, O> {
+    #[doc = "Write: clear error on writing '1'"]
+    #[inline(always)]
+    pub fn clear(self) -> &'a mut W {
+        self.variant(OVERREAD_AW::CLEAR)
+    }
+}
+#[doc = "Field `OVERFLOW` reader - RX buffer overflow detected, and prevented"]
+pub type OVERFLOW_R = crate::BitReader<OVERFLOW_A>;
+#[doc = "RX buffer overflow detected, and prevented\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum OVERFLOW_A {
+    #[doc = "0: Read: error not present"]
+    NOT_PRESENT = 0,
+    #[doc = "1: Read: error present"]
+    PRESENT = 1,
+}
+impl From<OVERFLOW_A> for bool {
+    #[inline(always)]
+    fn from(variant: OVERFLOW_A) -> Self {
+        variant as u8 != 0
+    }
+}
+impl OVERFLOW_R {
+    #[doc = "Get enumerated values variant"]
+    #[inline(always)]
+    pub fn variant(&self) -> OVERFLOW_A {
+        match self.bits {
+            false => OVERFLOW_A::NOT_PRESENT,
+            true => OVERFLOW_A::PRESENT,
+        }
+    }
+    #[doc = "Checks if the value of the field is `NOT_PRESENT`"]
+    #[inline(always)]
+    pub fn is_not_present(&self) -> bool {
+        *self == OVERFLOW_A::NOT_PRESENT
+    }
+    #[doc = "Checks if the value of the field is `PRESENT`"]
+    #[inline(always)]
+    pub fn is_present(&self) -> bool {
+        *self == OVERFLOW_A::PRESENT
+    }
+}
+#[doc = "RX buffer overflow detected, and prevented\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum OVERFLOW_AW {
+    #[doc = "1: Write: clear error on writing '1'"]
+    CLEAR = 1,
+}
+impl From<OVERFLOW_AW> for bool {
+    #[inline(always)]
+    fn from(variant: OVERFLOW_AW) -> Self {
+        variant as u8 != 0
+    }
+}
+#[doc = "Field `OVERFLOW` writer - RX buffer overflow detected, and prevented"]
+pub type OVERFLOW_W<'a, const O: u8> = crate::BitWriter<'a, u32, STATUS_SPEC, OVERFLOW_AW, O>;
+impl<'a, const O: u8> OVERFLOW_W<'a, O> {
+    #[doc = "Write: clear error on writing '1'"]
+    #[inline(always)]
+    pub fn clear(self) -> &'a mut W {
+        self.variant(OVERFLOW_AW::CLEAR)
+    }
+}
+impl R {
+    #[doc = "Bit 0 - TX buffer over-read detected, and prevented"]
+    #[inline(always)]
+    pub fn overread(&self) -> OVERREAD_R {
+        OVERREAD_R::new((self.bits & 1) != 0)
+    }
+    #[doc = "Bit 1 - RX buffer overflow detected, and prevented"]
+    #[inline(always)]
+    pub fn overflow(&self) -> OVERFLOW_R {
+        OVERFLOW_R::new(((self.bits >> 1) & 1) != 0)
+    }
+}
+impl W {
+    #[doc = "Bit 0 - TX buffer over-read detected, and prevented"]
+    #[inline(always)]
+    pub fn overread(&mut self) -> OVERREAD_W<0> {
+        OVERREAD_W::new(self)
+    }
+    #[doc = "Bit 1 - RX buffer overflow detected, and prevented"]
+    #[inline(always)]
+    pub fn overflow(&mut self) -> OVERFLOW_W<1> {
+        OVERFLOW_W::new(self)
+    }
+    #[doc = "Writes raw bits to the register."]
+    #[inline(always)]
+    pub unsafe fn bits(&mut self, bits: u32) -> &mut Self {
+        self.0.bits(bits);
+        self
+    }
+}
+#[doc = "Status from last transaction\n\nThis register you can [`read`](crate::generic::Reg::read), [`write_with_zero`](crate::generic::Reg::write_with_zero), [`reset`](crate::generic::Reg::reset), [`write`](crate::generic::Reg::write), [`modify`](crate::generic::Reg::modify). See [API](https://docs.rs/svd2rust/#read--modify--write-api).\n\nFor information about available fields see [status](index.html) module"]
+pub struct STATUS_SPEC;
+impl crate::RegisterSpec for STATUS_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [status::R](R) reader structure"]
+impl crate::Readable for STATUS_SPEC {
+    type Reader = R;
+}
+#[doc = "`write(|w| ..)` method takes [status::W](W) writer structure"]
+impl crate::Writable for STATUS_SPEC {
+    type Writer = W;
+}
+#[doc = "`reset()` method sets STATUS to value 0"]
+impl crate::Resettable for STATUS_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}