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/esp32s3/src/fe2/tx_interp_ctrl.rs

@@ -0,0 +1,62 @@
+#[doc = "Register `TX_INTERP_CTRL` reader"]
+pub type R = crate::R<TX_INTERP_CTRL_SPEC>;
+#[doc = "Register `TX_INTERP_CTRL` writer"]
+pub type W = crate::W<TX_INTERP_CTRL_SPEC>;
+#[doc = "Field `TX_INF_FORCE_PD` reader - Force Power Down field"]
+pub type TX_INF_FORCE_PD_R = crate::BitReader;
+#[doc = "Field `TX_INF_FORCE_PD` writer - Force Power Down field"]
+pub type TX_INF_FORCE_PD_W<'a, REG> = crate::BitWriter<'a, REG>;
+#[doc = "Field `TX_INF_FORCE_PU` reader - Force Power Up field"]
+pub type TX_INF_FORCE_PU_R = crate::BitReader;
+#[doc = "Field `TX_INF_FORCE_PU` writer - Force Power Up field"]
+pub type TX_INF_FORCE_PU_W<'a, REG> = crate::BitWriter<'a, REG>;
+impl R {
+    #[doc = "Bit 9 - Force Power Down field"]
+    #[inline(always)]
+    pub fn tx_inf_force_pd(&self) -> TX_INF_FORCE_PD_R {
+        TX_INF_FORCE_PD_R::new(((self.bits >> 9) & 1) != 0)
+    }
+    #[doc = "Bit 10 - Force Power Up field"]
+    #[inline(always)]
+    pub fn tx_inf_force_pu(&self) -> TX_INF_FORCE_PU_R {
+        TX_INF_FORCE_PU_R::new(((self.bits >> 10) & 1) != 0)
+    }
+}
+#[cfg(feature = "impl-register-debug")]
+impl core::fmt::Debug for R {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        f.debug_struct("TX_INTERP_CTRL")
+            .field("tx_inf_force_pu", &self.tx_inf_force_pu())
+            .field("tx_inf_force_pd", &self.tx_inf_force_pd())
+            .finish()
+    }
+}
+impl W {
+    #[doc = "Bit 9 - Force Power Down field"]
+    #[inline(always)]
+    pub fn tx_inf_force_pd(&mut self) -> TX_INF_FORCE_PD_W<TX_INTERP_CTRL_SPEC> {
+        TX_INF_FORCE_PD_W::new(self, 9)
+    }
+    #[doc = "Bit 10 - Force Power Up field"]
+    #[inline(always)]
+    pub fn tx_inf_force_pu(&mut self) -> TX_INF_FORCE_PU_W<TX_INTERP_CTRL_SPEC> {
+        TX_INF_FORCE_PU_W::new(self, 10)
+    }
+}
+#[doc = "FE2 TX Interpolation Control Register\n\nYou can [`read`](crate::Reg::read) this register and get [`tx_interp_ctrl::R`](R). You can [`reset`](crate::Reg::reset), [`write`](crate::Reg::write), [`write_with_zero`](crate::Reg::write_with_zero) this register using [`tx_interp_ctrl::W`](W). You can also [`modify`](crate::Reg::modify) this register. See [API](https://docs.rs/svd2rust/#read--modify--write-api)."]
+pub struct TX_INTERP_CTRL_SPEC;
+impl crate::RegisterSpec for TX_INTERP_CTRL_SPEC {
+    type Ux = u32;
+}
+#[doc = "`read()` method returns [`tx_interp_ctrl::R`](R) reader structure"]
+impl crate::Readable for TX_INTERP_CTRL_SPEC {}
+#[doc = "`write(|w| ..)` method takes [`tx_interp_ctrl::W`](W) writer structure"]
+impl crate::Writable for TX_INTERP_CTRL_SPEC {
+    type Safety = crate::Unsafe;
+    const ZERO_TO_MODIFY_FIELDS_BITMAP: u32 = 0;
+    const ONE_TO_MODIFY_FIELDS_BITMAP: u32 = 0;
+}
+#[doc = "`reset()` method sets TX_INTERP_CTRL to value 0"]
+impl crate::Resettable for TX_INTERP_CTRL_SPEC {
+    const RESET_VALUE: u32 = 0;
+}