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/nrf52833-pac/src/acl.rs

@@ -0,0 +1,33 @@
+#[doc = r"Register block"]
+#[repr(C)]
+pub struct RegisterBlock {
+    _reserved0: [u8; 0x0800],
+    #[doc = "0x800..0x80c - Unspecified"]
+    pub acl0: ACL,
+    _reserved1: [u8; 0x04],
+    #[doc = "0x810..0x81c - Unspecified"]
+    pub acl1: ACL,
+    _reserved2: [u8; 0x04],
+    #[doc = "0x820..0x82c - Unspecified"]
+    pub acl2: ACL,
+    _reserved3: [u8; 0x04],
+    #[doc = "0x830..0x83c - Unspecified"]
+    pub acl3: ACL,
+    _reserved4: [u8; 0x04],
+    #[doc = "0x840..0x84c - Unspecified"]
+    pub acl4: ACL,
+    _reserved5: [u8; 0x04],
+    #[doc = "0x850..0x85c - Unspecified"]
+    pub acl5: ACL,
+    _reserved6: [u8; 0x04],
+    #[doc = "0x860..0x86c - Unspecified"]
+    pub acl6: ACL,
+    _reserved7: [u8; 0x04],
+    #[doc = "0x870..0x87c - Unspecified"]
+    pub acl7: ACL,
+}
+#[doc = "Unspecified"]
+pub use acl::ACL;
+#[doc = r"Cluster"]
+#[doc = "Unspecified"]
+pub mod acl;