orchestrator: Construct ComponentId via From<u8>

Replace the ComponentId::new(idx as u8) call in poll_boot_walks with a
From<u8> conversion, per review. The const fn new stays for const
contexts (test constants).

Also assert N <= 256 at compile time in PlatformDriver::new: component
ids are u8, so a larger board would wrap them silently.

Signed-off-by: Christina Quast <christina.quast@9elements.com>

services/orchestrator/driver/src/driver.rs

diff --git a/services/orchestrator/driver/src/driver.rs b/services/orchestrator/driver/src/driver.rs
index 20dd800..5f3d9cc 100644
--- a/services/orchestrator/driver/src/driver.rs
+++ b/services/orchestrator/driver/src/driver.rs
@@ -54,6 +54,8 @@
 
 impl<B: BoardCapabilities, const N: usize> PlatformDriver<B, N> {
     pub fn new(board: Board<B, N>) -> Self {
+        // ComponentId is a u8, so ids for N > 256 components would wrap.
+        const { assert!(N <= 256) };
         Self {
             board,
             staged: None,
@@ -151,7 +153,7 @@
             if !self.watching[idx] {
                 continue;
             }
-            let id = ComponentId::new(idx as u8);
+            let id: ComponentId = (idx as u8).into();
             match self.board.boot_watches[idx].poll(now_millis) {
                 WalkVerdict::Waiting { deadline_millis } => {
                     next_deadline_millis = Some(match next_deadline_millis {

services/orchestrator/sm/src/model.rs

diff --git a/services/orchestrator/sm/src/model.rs b/services/orchestrator/sm/src/model.rs
index f921269..64ac92b 100644
--- a/services/orchestrator/sm/src/model.rs
+++ b/services/orchestrator/sm/src/model.rs
@@ -20,6 +20,12 @@
     }
 }
 
+impl From<u8> for ComponentId {
+    fn from(value: u8) -> Self {
+        Self(value)
+    }
+}
+
 /// How a component in the trust chain is classified. The board supplies one
 /// [`ComponentKind`] per [`ComponentId`] when building the chain.
 ///