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/acl.rs

@@ -0,0 +1,22 @@
+#[doc = r"Register block"]
+#[repr(C)]
+pub struct ACL {
+    #[doc = "0x00 - Description cluster: Configure the word-aligned start address of region n to protect"]
+    pub addr: ADDR,
+    #[doc = "0x04 - Description cluster: Size of region to protect counting from address ACL\\[n\\].ADDR. Write '0' as no effect."]
+    pub size: SIZE,
+    #[doc = "0x08 - Description cluster: Access permissions for region n as defined by start address ACL\\[n\\].ADDR and size ACL\\[n\\].SIZE"]
+    pub perm: PERM,
+}
+#[doc = "ADDR (rw) register accessor: an alias for `Reg<ADDR_SPEC>`"]
+pub type ADDR = crate::Reg<addr::ADDR_SPEC>;
+#[doc = "Description cluster: Configure the word-aligned start address of region n to protect"]
+pub mod addr;
+#[doc = "SIZE (rw) register accessor: an alias for `Reg<SIZE_SPEC>`"]
+pub type SIZE = crate::Reg<size::SIZE_SPEC>;
+#[doc = "Description cluster: Size of region to protect counting from address ACL\\[n\\].ADDR. Write '0' as no effect."]
+pub mod size;
+#[doc = "PERM (rw) register accessor: an alias for `Reg<PERM_SPEC>`"]
+pub type PERM = crate::Reg<perm::PERM_SPEC>;
+#[doc = "Description cluster: Access permissions for region n as defined by start address ACL\\[n\\].ADDR and size ACL\\[n\\].SIZE"]
+pub mod perm;