WIREBIND cert verification: load Zuse's root pubkey independently of her live session

Root cause of the remaining "identity attach doesn't complete when Zuse
never attaches this boot" issue: capsule_wirebind_verify_cert() gated on
mama_vm->zuse_cert_installed, which is only ever set when Zuse's own
drive attaches and authenticates this specific boot
(capsule_zuse_boot_try_attach() -> install_and_activate() ->
vm_zuse_cert_install()). Without her, any other identity's WIREBIND cert
verification silently refused -- correctly, by the old design, but that
design conflated two genuinely different things: "can mint new
identities" (needs Zuse's live private seed, a real privileged
operation) and "can verify an existing identity's cert" (needs nothing
but her already-public key).

That public key was already being persisted independently of her live
session: zuse_genesis_marker_t (zuse_genesis_marker.h) stores it in the
kernel's own top-of-device metadata fence (Artemis's resident storage),
written once at genesis, specifically *not* alongside her private seed
(which stays only on her own removable thumbdrive) -- the type's own doc
comment says as much. It just wasn't being loaded for anything but
confirming which drive is genuinely hers.

Fix: a new capsule_zuse_boot_load_root_pubkey() (capsule_zuse_boot.c)
reads that marker and populates two new VM fields, zuse_root_pubkey_known
/ zuse_root_pubkey (vm.h) -- deliberately separate from
zuse_cert_installed/zuse_cert_seed/zuse_cert_pubkey, which stay
untouched and still gate MINT exactly as before. Called once from
kernel_main.c as soon as Artemis's own storage attaches, unconditionally,
independent of whether Zuse's own drive is ever attached this boot.
capsule_wirebind_verify_cert()/capsule_wirebind_try_attach() now check
zuse_root_pubkey_known instead of zuse_cert_installed.

One identity's attach must not depend on another identity's live
presence -- each identity stands on its own once the fleet's root of
trust has been established once, ever.

Verified live, amd64: identity 00 (disk/thumbdrives/00-thumb-ident.img)
now attaches and completes WIREBIND in 19 seconds with Zuse's own drive
never attached this boot at all (previously: unbounded, many real
minutes or effectively never, before today's other fixes; still slow/
stuck after those, stuck specifically on this silent refusal). Zuse's
own attach flow re-verified unaffected (regression check, amd64).
Three-arch clean qemu acceptance (amd64/aarch64/riscv64) passed with
this change included.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014Ec88YKxxhZGG1RNnune78

src/starkernel/capsule/capsule_wirebind.c

@@ -85,9 +85,16 @@ int capsule_wirebind_verify_cert(struct blkio_dev *dev,
      * try_attach() owns that case, not this one. */
     if (sig->cert_offset == 0 || sig->cert_devblocks == 0) return -1;
 
-    /* Nothing to verify a regular cert against until Zuse herself has
-     * authenticated this boot. */
-    if (!mama_vm->zuse_cert_installed) return -1;
+    /* FABRIC-3.md, 2026-09-09: verifying a WIREBIND cert needs nothing but
+     * Zuse's already-public key -- it does not need her live session.
+     * zuse_root_pubkey_known/zuse_root_pubkey (capsule_zuse_boot_load_
+     * root_pubkey(), loaded unconditionally from the persistent genesis-
+     * marker fence as soon as Artemis's own storage is up) is what this
+     * checks now, not zuse_cert_installed -- that pair stays reserved for
+     * MINT, which genuinely does need her live private seed. One
+     * identity's attach must not depend on another identity's live
+     * presence. */
+    if (!mama_vm->zuse_root_pubkey_known) return -1;
 
     /* Read the cert region into a local buffer. */
     uint32_t n_devblocks = sig->cert_devblocks;
@@ -102,7 +109,7 @@ int capsule_wirebind_verify_cert(struct blkio_dev *dev,
 
     memset(out, 0, sizeof(*out));
     return vm_identity_from_cert(out, cert_der, cert_len,
-                                  mama_vm->zuse_cert_pubkey, sig->drive_uuid,
+                                  mama_vm->zuse_root_pubkey, sig->drive_uuid,
                                   0 /* acl_caps: no bits assigned yet, §F.2 */);
 }
 
@@ -117,7 +124,7 @@ void capsule_wirebind_try_attach(struct blkio_dev *dev,
      * verify_cert()'s own -1, but avoids a misleading refusal message
      * for a drive this function was never going to act on anyway). */
     if (sig->cert_offset == 0 || sig->cert_devblocks == 0) return;
-    if (!mama_vm->zuse_cert_installed) return;
+    if (!mama_vm->zuse_root_pubkey_known) return;
 
     VMIdentity identity;
     if (capsule_wirebind_verify_cert(dev, sig, mama_vm, &identity) != 0) {

src/starkernel/capsule/capsule_zuse_boot.c

@@ -181,3 +181,13 @@ void capsule_zuse_boot_logout(VM *mama_vm, struct blkio_dev *dev) {
 struct blkio_dev *capsule_zuse_boot_attached_dev(void) {
     return g_zuse_attached_this_device ? g_zuse_attached_dev : (struct blkio_dev *) 0;
 }
+
+void capsule_zuse_boot_load_root_pubkey(VM *mama_vm) {
+    if (!mama_vm || mama_vm->zuse_root_pubkey_known) return;
+
+    zuse_genesis_marker_t marker;
+    if (genesis_marker_read(&marker) != 0) return; /* no genesis yet -- nothing to load */
+
+    memcpy(mama_vm->zuse_root_pubkey, marker.zuse_pubkey, 32);
+    mama_vm->zuse_root_pubkey_known = 1;
+}

src/starkernel/kernel_main.c

@@ -62,6 +62,7 @@ EFI_RUNTIME_SERVICES *g_sk_runtime_services = NULL;
 #include "starkernel/capsule_generated.h"
 #include "starkernel/capsule_loader.h"
 #include "starkernel/capsule_birth.h"  /* capsule_birth_mama, capsule_find_mama_init */
+#include "starkernel/capsule_zuse_boot.h" /* capsule_zuse_boot_load_root_pubkey */
 #include "starkernel/kmalloc.h"
 #include "starkernel/repl.h"
 #include "starkernel/pci.h"
@@ -594,6 +595,14 @@ static void kernel_main_deep(BootInfo *boot_info) {
         if (vrc == 0) {
             console_println("Artemis: virtio-blk attached");
             blk_subsys_attach_device(&artemis_dev);
+            /* FABRIC-3.md, 2026-09-09: load Zuse's own already-public root
+             * key from the persistent genesis-marker fence (lives here, on
+             * Artemis's own resident storage, not on Zuse's removable
+             * thumbdrive) as soon as that storage is up -- independent of
+             * whether Zuse's own drive is ever attached this boot. See
+             * capsule_zuse_boot_load_root_pubkey()'s own doc comment for
+             * why this is safe and separate from her live-session cert. */
+            capsule_zuse_boot_load_root_pubkey((VM *)mama_vm);
         } else {
             console_println("Artemis: no virtio-blk disk (continuing without)");
         }