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/nrf52832-pac/src/ficr/nfc.rs

@@ -0,0 +1,28 @@
+#[doc = r"Register block"]
+#[repr(C)]
+pub struct NFC {
+    #[doc = "0x00 - Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+    pub tagheader0: TAGHEADER0,
+    #[doc = "0x04 - Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+    pub tagheader1: TAGHEADER1,
+    #[doc = "0x08 - Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+    pub tagheader2: TAGHEADER2,
+    #[doc = "0x0c - Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+    pub tagheader3: TAGHEADER3,
+}
+#[doc = "TAGHEADER0 (r) register accessor: an alias for `Reg<TAGHEADER0_SPEC>`"]
+pub type TAGHEADER0 = crate::Reg<tagheader0::TAGHEADER0_SPEC>;
+#[doc = "Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+pub mod tagheader0;
+#[doc = "TAGHEADER1 (r) register accessor: an alias for `Reg<TAGHEADER1_SPEC>`"]
+pub type TAGHEADER1 = crate::Reg<tagheader1::TAGHEADER1_SPEC>;
+#[doc = "Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+pub mod tagheader1;
+#[doc = "TAGHEADER2 (r) register accessor: an alias for `Reg<TAGHEADER2_SPEC>`"]
+pub type TAGHEADER2 = crate::Reg<tagheader2::TAGHEADER2_SPEC>;
+#[doc = "Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+pub mod tagheader2;
+#[doc = "TAGHEADER3 (r) register accessor: an alias for `Reg<TAGHEADER3_SPEC>`"]
+pub type TAGHEADER3 = crate::Reg<tagheader3::TAGHEADER3_SPEC>;
+#[doc = "Default header for NFC Tag. Software can read these values to populate NFCID1_3RD_LAST, NFCID1_2ND_LAST and NFCID1_LAST."]
+pub mod tagheader3;