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/cache_s/profiling/dhit.rs

@@ -0,0 +1,40 @@
+#[doc = "Register `DHIT` reader"]
+pub struct R(crate::R<DHIT_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<DHIT_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<DHIT_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<DHIT_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Field `HITS` reader - Number of data cache hits"]
+pub type HITS_R = crate::FieldReader<u32, u32>;
+impl R {
+    #[doc = "Bits 0:31 - Number of data cache hits"]
+    #[inline(always)]
+    pub fn hits(&self) -> HITS_R {
+        HITS_R::new(self.bits)
+    }
+}
+#[doc = "Description cluster: Data fetch cache hit counter for cache region n, where n=0 means Flash and n=1 means XIP.\n\nThis register you can [`read`](crate::generic::Reg::read). See [API](https://docs.rs/svd2rust/#read--modify--write-api).\n\nFor information about available fields see [dhit](index.html) module"]
+pub struct DHIT_SPEC;
+impl crate::RegisterSpec for DHIT_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [dhit::R](R) reader structure"]
+impl crate::Readable for DHIT_SPEC {
+    type Reader = R;
+}
+#[doc = "`reset()` method sets DHIT to value 0"]
+impl crate::Resettable for DHIT_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}

vendor/nrf5340-app-pac/src/cache_s/profiling/dmiss.rs

@@ -0,0 +1,40 @@
+#[doc = "Register `DMISS` reader"]
+pub struct R(crate::R<DMISS_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<DMISS_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<DMISS_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<DMISS_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Field `MISSES` reader - Number of data cache misses"]
+pub type MISSES_R = crate::FieldReader<u32, u32>;
+impl R {
+    #[doc = "Bits 0:31 - Number of data cache misses"]
+    #[inline(always)]
+    pub fn misses(&self) -> MISSES_R {
+        MISSES_R::new(self.bits)
+    }
+}
+#[doc = "Description cluster: Data fetch cache miss counter for cache region n, where n=0 means Flash and n=1 means XIP.\n\nThis register you can [`read`](crate::generic::Reg::read). See [API](https://docs.rs/svd2rust/#read--modify--write-api).\n\nFor information about available fields see [dmiss](index.html) module"]
+pub struct DMISS_SPEC;
+impl crate::RegisterSpec for DMISS_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [dmiss::R](R) reader structure"]
+impl crate::Readable for DMISS_SPEC {
+    type Reader = R;
+}
+#[doc = "`reset()` method sets DMISS to value 0"]
+impl crate::Resettable for DMISS_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}

vendor/nrf5340-app-pac/src/cache_s/profiling/ihit.rs

@@ -0,0 +1,40 @@
+#[doc = "Register `IHIT` reader"]
+pub struct R(crate::R<IHIT_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<IHIT_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<IHIT_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<IHIT_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Field `HITS` reader - Number of instruction cache hits"]
+pub type HITS_R = crate::FieldReader<u32, u32>;
+impl R {
+    #[doc = "Bits 0:31 - Number of instruction cache hits"]
+    #[inline(always)]
+    pub fn hits(&self) -> HITS_R {
+        HITS_R::new(self.bits)
+    }
+}
+#[doc = "Description cluster: Instruction fetch cache hit counter for cache region n, where n=0 means Flash and n=1 means XIP.\n\nThis register you can [`read`](crate::generic::Reg::read). See [API](https://docs.rs/svd2rust/#read--modify--write-api).\n\nFor information about available fields see [ihit](index.html) module"]
+pub struct IHIT_SPEC;
+impl crate::RegisterSpec for IHIT_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [ihit::R](R) reader structure"]
+impl crate::Readable for IHIT_SPEC {
+    type Reader = R;
+}
+#[doc = "`reset()` method sets IHIT to value 0"]
+impl crate::Resettable for IHIT_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}

vendor/nrf5340-app-pac/src/cache_s/profiling/imiss.rs

@@ -0,0 +1,40 @@
+#[doc = "Register `IMISS` reader"]
+pub struct R(crate::R<IMISS_SPEC>);
+impl core::ops::Deref for R {
+    type Target = crate::R<IMISS_SPEC>;
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+impl From<crate::R<IMISS_SPEC>> for R {
+    #[inline(always)]
+    fn from(reader: crate::R<IMISS_SPEC>) -> Self {
+        R(reader)
+    }
+}
+#[doc = "Field `MISSES` reader - Number of instruction cache misses"]
+pub type MISSES_R = crate::FieldReader<u32, u32>;
+impl R {
+    #[doc = "Bits 0:31 - Number of instruction cache misses"]
+    #[inline(always)]
+    pub fn misses(&self) -> MISSES_R {
+        MISSES_R::new(self.bits)
+    }
+}
+#[doc = "Description cluster: Instruction fetch cache miss counter for cache region n, where n=0 means Flash and n=1 means XIP.\n\nThis register you can [`read`](crate::generic::Reg::read). See [API](https://docs.rs/svd2rust/#read--modify--write-api).\n\nFor information about available fields see [imiss](index.html) module"]
+pub struct IMISS_SPEC;
+impl crate::RegisterSpec for IMISS_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [imiss::R](R) reader structure"]
+impl crate::Readable for IMISS_SPEC {
+    type Reader = R;
+}
+#[doc = "`reset()` method sets IMISS to value 0"]
+impl crate::Resettable for IMISS_SPEC {
+    #[inline(always)]
+    fn reset_value() -> Self::Ux {
+        0
+    }
+}