feat(boot): gatekeeper gates boot (init→UI→gatekeeper→data); keystore disk + virtio-rng discovery; terminal READ_SECRET; storage SET_KEY; PageCount ≤8192, alloc cap gone; device window 0x01D0_0000; test-qemu types passcode over 2 boots

crates/kernel/src/tests/abi.rs

@@ -70,7 +70,11 @@ fn out_of_range_arguments_do_not_decode() {
         decode(SYS_REQUEST_PAGES, &[0, 0, 0, 0, 0, 0]).is_none(),
         "zero pages"
     );
-    assert!(decode(SYS_REQUEST_PAGES, &[1025, 0, 0, 0, 0, 0]).is_none());
+    let too_many = types::bounded::PageCount::MAX as usize + 1;
+    assert!(
+        decode(SYS_REQUEST_PAGES, &[too_many, 0, 0, 0, 0, 0]).is_none(),
+        "more pages than one request may ask for"
+    );
     assert!(
         decode(SYS_MAP_REGION, &[1, 0x30000, 3, 0, 0, 0]).is_none(),
         "bad perms"