feat: migrate to embassy-executor 0.10

Bump embassy-executor 0.9 -> 0.10 and embassy-rp 0.9 -> 0.10 from crates.io.
Patch esp-hal, esp-rtos, esp-backtrace, esp-println from esp-rs/esp-hal main
branch (esp-rtos 0.2.0 on crates.io pins embassy-executor ^0.9).

API migrations:
- embassy-executor: arch-cortex-m -> platform-cortex-m feature rename
- embassy-executor: SpawnToken now returned as Result from task functions
- esp-hal main: efuse::Efuse::mac_address() -> efuse::base_mac_address()
- esp-hal main: esp_rtos::start() now requires SoftwareInterrupt<0>
- embassy-rp 0.10: SPI constructor requires DMA interrupt bindings

Also fixes UART display stuck on splash (sent Reset instead of On at boot)
and switches just check to clippy -D warnings.

src/host/uart.rs

@@ -20,9 +20,9 @@ pub async fn host_task(
 ) {
     let (mut rx, mut tx) = parts.driver.split();
 
-    // UART has no DTR — signal the display that a host is present at boot.
+    // UART has no DTR — assume a host is always present.
     if has_display {
-        display_commands.send(DisplayCommand::Reset).await;
+        display_commands.send(DisplayCommand::On).await;
     }
 
     let mut read_buf = [0u8; 64];