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/nrf5340-app-pac/src/cacheinfo_s/set.rs

@@ -0,0 +1,10 @@
+#[doc = r"Register block"]
+#[repr(C)]
+pub struct SET {
+    #[doc = "0x00..0x08 - Description collection: Cache information for SET\\[n\\], WAY\\[o\\]."]
+    pub way: [WAY; 2],
+}
+#[doc = "WAY (rw) register accessor: an alias for `Reg<WAY_SPEC>`"]
+pub type WAY = crate::Reg<way::WAY_SPEC>;
+#[doc = "Description collection: Cache information for SET\\[n\\], WAY\\[o\\]."]
+pub mod way;

vendor/nrf5340-app-pac/src/cacheinfo_s/set/way.rs

@@ -0,0 +1,163 @@
+#[doc = "Register `WAY[%s]` reader"]
+pub struct R(crate::R<WAY_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<WAY_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<WAY_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<WAY_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Register `WAY[%s]` writer"]
+pub struct W(crate::W<WAY_SPEC>);
+impl core::ops::Deref for W {
+    type Target = crate::W<WAY_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<WAY_SPEC>> for W {
+    #[inline(always)]
+    fn from(writer: crate::W<WAY_SPEC>) -> Self {
+        W(writer)
+    }
+}
+#[doc = "Field `TAG` reader - Cache tag."]
+pub type TAG_R = crate::FieldReader<u32, u32>;
+#[doc = "Field `TAG` writer - Cache tag."]
+pub type TAG_W<'a, const O: u8> = crate::FieldWriter<'a, u32, WAY_SPEC, u32, u32, 17, O>;
+#[doc = "Field `V` reader - Valid bit"]
+pub type V_R = crate::BitReader<V_A>;
+#[doc = "Valid bit\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum V_A {
+    #[doc = "0: Invalid cache line"]
+    INVALID = 0,
+    #[doc = "1: Valid cache line"]
+    VALID = 1,
+}
+impl From<V_A> for bool {
+    #[inline(always)]
+    fn from(variant: V_A) -> Self {
+        variant as u8 != 0
+    }
+}
+impl V_R {
+    #[doc = "Get enumerated values variant"]
+    #[inline(always)]
+    pub fn variant(&self) -> V_A {
+        match self.bits {
+            false => V_A::INVALID,
+            true => V_A::VALID,
+        }
+    }
+    #[doc = "Checks if the value of the field is `INVALID`"]
+    #[inline(always)]
+    pub fn is_invalid(&self) -> bool {
+        *self == V_A::INVALID
+    }
+    #[doc = "Checks if the value of the field is `VALID`"]
+    #[inline(always)]
+    pub fn is_valid(&self) -> bool {
+        *self == V_A::VALID
+    }
+}
+#[doc = "Field `MRU` reader - Most recently used way."]
+pub type MRU_R = crate::BitReader<MRU_A>;
+#[doc = "Most recently used way.\n\nValue on reset: 0"]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum MRU_A {
+    #[doc = "0: Way0 was most recently used"]
+    WAY0 = 0,
+    #[doc = "1: Way1 was most recently used"]
+    WAY1 = 1,
+}
+impl From<MRU_A> for bool {
+    #[inline(always)]
+    fn from(variant: MRU_A) -> Self {
+        variant as u8 != 0
+    }
+}
+impl MRU_R {
+    #[doc = "Get enumerated values variant"]
+    #[inline(always)]
+    pub fn variant(&self) -> MRU_A {
+        match self.bits {
+            false => MRU_A::WAY0,
+            true => MRU_A::WAY1,
+        }
+    }
+    #[doc = "Checks if the value of the field is `WAY0`"]
+    #[inline(always)]
+    pub fn is_way0(&self) -> bool {
+        *self == MRU_A::WAY0
+    }
+    #[doc = "Checks if the value of the field is `WAY1`"]
+    #[inline(always)]
+    pub fn is_way1(&self) -> bool {
+        *self == MRU_A::WAY1
+    }
+}
+impl R {
+    #[doc = "Bits 0:16 - Cache tag."]
+    #[inline(always)]
+    pub fn tag(&self) -> TAG_R {
+        TAG_R::new((self.bits & 0x0001_ffff) as u32)
+    }
+    #[doc = "Bit 30 - Valid bit"]
+    #[inline(always)]
+    pub fn v(&self) -> V_R {
+        V_R::new(((self.bits >> 30) & 1) != 0)
+    }
+    #[doc = "Bit 31 - Most recently used way."]
+    #[inline(always)]
+    pub fn mru(&self) -> MRU_R {
+        MRU_R::new(((self.bits >> 31) & 1) != 0)
+    }
+}
+impl W {
+    #[doc = "Bits 0:16 - Cache tag."]
+    #[inline(always)]
+    pub fn tag(&mut self) -> TAG_W<0> {
+        TAG_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 = "Description collection: Cache information for SET\\[n\\], WAY\\[o\\].\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 [way](index.html) module"]
+pub struct WAY_SPEC;
+impl crate::RegisterSpec for WAY_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [way::R](R) reader structure"]
+impl crate::Readable for WAY_SPEC {
+    type Reader = R;
+}
+#[doc = "`write(|w| ..)` method takes [way::W](W) writer structure"]
+impl crate::Writable for WAY_SPEC {
+    type Writer = W;
+}
+#[doc = "`reset()` method sets WAY[%s]
+to value 0"]
+impl crate::Resettable for WAY_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}