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/nrf51-pac/src/spis1.rs

@@ -0,0 +1,170 @@
+#[doc = r"Register block"]
+#[repr(C)]
+pub struct RegisterBlock {
+    _reserved0: [u8; 0x24],
+    #[doc = "0x24 - Acquire SPI semaphore."]
+    pub tasks_acquire: TASKS_ACQUIRE,
+    #[doc = "0x28 - Release SPI semaphore."]
+    pub tasks_release: TASKS_RELEASE,
+    _reserved2: [u8; 0xd8],
+    #[doc = "0x104 - Granted transaction completed."]
+    pub events_end: EVENTS_END,
+    _reserved3: [u8; 0x08],
+    #[doc = "0x110 - End of RXD buffer reached"]
+    pub events_endrx: EVENTS_ENDRX,
+    _reserved4: [u8; 0x14],
+    #[doc = "0x128 - Semaphore acquired."]
+    pub events_acquired: EVENTS_ACQUIRED,
+    _reserved5: [u8; 0xd4],
+    #[doc = "0x200 - Shortcuts for SPIS."]
+    pub shorts: SHORTS,
+    _reserved6: [u8; 0x0100],
+    #[doc = "0x304 - Interrupt enable set register."]
+    pub intenset: INTENSET,
+    #[doc = "0x308 - Interrupt enable clear register."]
+    pub intenclr: INTENCLR,
+    _reserved8: [u8; 0xf4],
+    #[doc = "0x400 - Semaphore status."]
+    pub semstat: SEMSTAT,
+    _reserved9: [u8; 0x3c],
+    #[doc = "0x440 - Status from last transaction."]
+    pub status: STATUS,
+    _reserved10: [u8; 0xbc],
+    #[doc = "0x500 - Enable SPIS."]
+    pub enable: ENABLE,
+    _reserved11: [u8; 0x04],
+    #[doc = "0x508 - Pin select for SCK."]
+    pub pselsck: PSELSCK,
+    #[doc = "0x50c - Pin select for MISO."]
+    pub pselmiso: PSELMISO,
+    #[doc = "0x510 - Pin select for MOSI."]
+    pub pselmosi: PSELMOSI,
+    #[doc = "0x514 - Pin select for CSN."]
+    pub pselcsn: PSELCSN,
+    _reserved15: [u8; 0x1c],
+    #[doc = "0x534 - RX data pointer."]
+    pub rxdptr: RXDPTR,
+    #[doc = "0x538 - Maximum number of bytes in the receive buffer."]
+    pub maxrx: MAXRX,
+    #[doc = "0x53c - Number of bytes received in last granted transaction."]
+    pub amountrx: AMOUNTRX,
+    _reserved18: [u8; 0x04],
+    #[doc = "0x544 - TX data pointer."]
+    pub txdptr: TXDPTR,
+    #[doc = "0x548 - Maximum number of bytes in the transmit buffer."]
+    pub maxtx: MAXTX,
+    #[doc = "0x54c - Number of bytes transmitted in last granted transaction."]
+    pub amounttx: AMOUNTTX,
+    _reserved21: [u8; 0x04],
+    #[doc = "0x554 - Configuration register."]
+    pub config: CONFIG,
+    _reserved22: [u8; 0x04],
+    #[doc = "0x55c - Default character."]
+    pub def: DEF,
+    _reserved23: [u8; 0x60],
+    #[doc = "0x5c0 - Over-read character."]
+    pub orc: ORC,
+    _reserved24: [u8; 0x0a38],
+    #[doc = "0xffc - Peripheral power control."]
+    pub power: POWER,
+}
+#[doc = "TASKS_ACQUIRE (w) register accessor: an alias for `Reg<TASKS_ACQUIRE_SPEC>`"]
+pub type TASKS_ACQUIRE = crate::Reg<tasks_acquire::TASKS_ACQUIRE_SPEC>;
+#[doc = "Acquire SPI semaphore."]
+pub mod tasks_acquire;
+#[doc = "TASKS_RELEASE (w) register accessor: an alias for `Reg<TASKS_RELEASE_SPEC>`"]
+pub type TASKS_RELEASE = crate::Reg<tasks_release::TASKS_RELEASE_SPEC>;
+#[doc = "Release SPI semaphore."]
+pub mod tasks_release;
+#[doc = "EVENTS_END (rw) register accessor: an alias for `Reg<EVENTS_END_SPEC>`"]
+pub type EVENTS_END = crate::Reg<events_end::EVENTS_END_SPEC>;
+#[doc = "Granted transaction completed."]
+pub mod events_end;
+#[doc = "EVENTS_ENDRX (rw) register accessor: an alias for `Reg<EVENTS_ENDRX_SPEC>`"]
+pub type EVENTS_ENDRX = crate::Reg<events_endrx::EVENTS_ENDRX_SPEC>;
+#[doc = "End of RXD buffer reached"]
+pub mod events_endrx;
+#[doc = "EVENTS_ACQUIRED (rw) register accessor: an alias for `Reg<EVENTS_ACQUIRED_SPEC>`"]
+pub type EVENTS_ACQUIRED = crate::Reg<events_acquired::EVENTS_ACQUIRED_SPEC>;
+#[doc = "Semaphore acquired."]
+pub mod events_acquired;
+#[doc = "SHORTS (rw) register accessor: an alias for `Reg<SHORTS_SPEC>`"]
+pub type SHORTS = crate::Reg<shorts::SHORTS_SPEC>;
+#[doc = "Shortcuts for SPIS."]
+pub mod shorts;
+#[doc = "INTENSET (rw) register accessor: an alias for `Reg<INTENSET_SPEC>`"]
+pub type INTENSET = crate::Reg<intenset::INTENSET_SPEC>;
+#[doc = "Interrupt enable set register."]
+pub mod intenset;
+#[doc = "INTENCLR (rw) register accessor: an alias for `Reg<INTENCLR_SPEC>`"]
+pub type INTENCLR = crate::Reg<intenclr::INTENCLR_SPEC>;
+#[doc = "Interrupt enable clear register."]
+pub mod intenclr;
+#[doc = "SEMSTAT (r) register accessor: an alias for `Reg<SEMSTAT_SPEC>`"]
+pub type SEMSTAT = crate::Reg<semstat::SEMSTAT_SPEC>;
+#[doc = "Semaphore status."]
+pub mod semstat;
+#[doc = "STATUS (rw) register accessor: an alias for `Reg<STATUS_SPEC>`"]
+pub type STATUS = crate::Reg<status::STATUS_SPEC>;
+#[doc = "Status from last transaction."]
+pub mod status;
+#[doc = "ENABLE (rw) register accessor: an alias for `Reg<ENABLE_SPEC>`"]
+pub type ENABLE = crate::Reg<enable::ENABLE_SPEC>;
+#[doc = "Enable SPIS."]
+pub mod enable;
+#[doc = "PSELSCK (rw) register accessor: an alias for `Reg<PSELSCK_SPEC>`"]
+pub type PSELSCK = crate::Reg<pselsck::PSELSCK_SPEC>;
+#[doc = "Pin select for SCK."]
+pub mod pselsck;
+#[doc = "PSELMISO (rw) register accessor: an alias for `Reg<PSELMISO_SPEC>`"]
+pub type PSELMISO = crate::Reg<pselmiso::PSELMISO_SPEC>;
+#[doc = "Pin select for MISO."]
+pub mod pselmiso;
+#[doc = "PSELMOSI (rw) register accessor: an alias for `Reg<PSELMOSI_SPEC>`"]
+pub type PSELMOSI = crate::Reg<pselmosi::PSELMOSI_SPEC>;
+#[doc = "Pin select for MOSI."]
+pub mod pselmosi;
+#[doc = "PSELCSN (rw) register accessor: an alias for `Reg<PSELCSN_SPEC>`"]
+pub type PSELCSN = crate::Reg<pselcsn::PSELCSN_SPEC>;
+#[doc = "Pin select for CSN."]
+pub mod pselcsn;
+#[doc = "RXDPTR (rw) register accessor: an alias for `Reg<RXDPTR_SPEC>`"]
+pub type RXDPTR = crate::Reg<rxdptr::RXDPTR_SPEC>;
+#[doc = "RX data pointer."]
+pub mod rxdptr;
+#[doc = "MAXRX (rw) register accessor: an alias for `Reg<MAXRX_SPEC>`"]
+pub type MAXRX = crate::Reg<maxrx::MAXRX_SPEC>;
+#[doc = "Maximum number of bytes in the receive buffer."]
+pub mod maxrx;
+#[doc = "AMOUNTRX (r) register accessor: an alias for `Reg<AMOUNTRX_SPEC>`"]
+pub type AMOUNTRX = crate::Reg<amountrx::AMOUNTRX_SPEC>;
+#[doc = "Number of bytes received in last granted transaction."]
+pub mod amountrx;
+#[doc = "TXDPTR (rw) register accessor: an alias for `Reg<TXDPTR_SPEC>`"]
+pub type TXDPTR = crate::Reg<txdptr::TXDPTR_SPEC>;
+#[doc = "TX data pointer."]
+pub mod txdptr;
+#[doc = "MAXTX (rw) register accessor: an alias for `Reg<MAXTX_SPEC>`"]
+pub type MAXTX = crate::Reg<maxtx::MAXTX_SPEC>;
+#[doc = "Maximum number of bytes in the transmit buffer."]
+pub mod maxtx;
+#[doc = "AMOUNTTX (r) register accessor: an alias for `Reg<AMOUNTTX_SPEC>`"]
+pub type AMOUNTTX = crate::Reg<amounttx::AMOUNTTX_SPEC>;
+#[doc = "Number of bytes transmitted in last granted transaction."]
+pub mod amounttx;
+#[doc = "CONFIG (rw) register accessor: an alias for `Reg<CONFIG_SPEC>`"]
+pub type CONFIG = crate::Reg<config::CONFIG_SPEC>;
+#[doc = "Configuration register."]
+pub mod config;
+#[doc = "DEF (rw) register accessor: an alias for `Reg<DEF_SPEC>`"]
+pub type DEF = crate::Reg<def::DEF_SPEC>;
+#[doc = "Default character."]
+pub mod def;
+#[doc = "ORC (rw) register accessor: an alias for `Reg<ORC_SPEC>`"]
+pub type ORC = crate::Reg<orc::ORC_SPEC>;
+#[doc = "Over-read character."]
+pub mod orc;
+#[doc = "POWER (rw) register accessor: an alias for `Reg<POWER_SPEC>`"]
+pub type POWER = crate::Reg<power::POWER_SPEC>;
+#[doc = "Peripheral power control."]
+pub mod power;