Zuse default-attach: xHCI initial-port-scan fix, ZUSEDISK wiring, mismatched-marker resync

xhci_bringup() now scans for already-connected ports at bring-up
(xhci_scan_ports_for_already_connected()), not just later hotplug events,
so a USB device present on the QEMU command line at launch is detected.
Makefile.starkernel attaches disk/zuse.img on the xhci0 bus by default in
all three arch qemu targets (ZUSEDISK=, empties for a bare boot).

capsule_mint_identity() gained a drive_known_blank param to skip a fully
redundant second homeblocks_sig_check() when the caller already confirmed
HOMEBLOCKS_SIG_BLANK itself.

Root-caused what looked like a hang after the drive attached: Artemis's
fence still carried a genesis marker from before a mid-session reformat,
while the reformatted disk/zuse.img read back BLANK -- a mismatched pair
capsule_zuse_boot_try_attach() correctly declined to act on, leaving the
boot idling at a plain ok> with nothing left to log (indistinguishable
from a hang under slow TCG). Fixed by zeroing both disk/artemis.img and
disk/zuse.img at their original sizes, giving a matched blank pair.
Verified full three-architecture acceptance: amd64 fresh genesis-mint,
aarch64/riscv64 clean reload against the same now-minted images.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KBjfeLPo71sUQ8zC7V7P5m

src/starkernel/capsule/capsule_mint.c

@@ -59,7 +59,8 @@ static int write_devblock(struct blkio_dev *dev, uint32_t devblock,
 MintResult capsule_mint_identity(struct blkio_dev *dev, VM *issuer_vm,
                                   const char *full_name, const char *username,
                                   const char *email, const char *phone,
-                                  uint8_t out_pubkey[32], uint8_t out_seed[32]) {
+                                  uint8_t out_pubkey[32], uint8_t out_seed[32],
+                                  int drive_known_blank) {
     if (!dev || !full_name || !username) return MINT_ERR_WRITE_FAIL;
 
     /* full_name/username required and must fit; email/phone may be NULL
@@ -75,8 +76,11 @@ MintResult capsule_mint_identity(struct blkio_dev *dev, VM *issuer_vm,
 
     /* Refuse to overwrite an already-recognized home-blocks drive --
      * mirrors WRITE(10)'s own refuse-on-non-blank-media posture (§F.8,
-     * decided 2026-08-28: "reasonable by analogy" there, now decided). */
-    {
+     * decided 2026-08-28: "reasonable by analogy" there, now decided).
+     * Skipped when the caller already just confirmed HOMEBLOCKS_SIG_BLANK
+     * itself (drive_known_blank) -- otherwise this repeats the exact same
+     * full BOT read sequence a second time immediately after the first. */
+    if (!drive_known_blank) {
         homeblocks_sig_t existing;
         if (homeblocks_sig_check(dev, HOMEBLOCKS_SIG_START_FBLOCK, &existing)
             == HOMEBLOCKS_SIG_OK) {

src/starkernel/capsule/capsule_zuse_boot.c

@@ -73,7 +73,8 @@ void capsule_zuse_boot_try_attach(struct blkio_dev *dev,
         uint8_t seed[32], pubkey[32];
         MintResult r = capsule_mint_identity(dev, (VM *)0, "Zuse", "zuse",
                                               (const char *)0, (const char *)0,
-                                              pubkey, seed);
+                                              pubkey, seed,
+                                              1 /* sig_rc already confirmed BLANK above */);
         if (r != MINT_OK) {
             console_println("Zuse: genesis mint failed");
             return;

src/starkernel/capsule/mama_forth_words.c

@@ -868,7 +868,8 @@ static void mama_word_mint(VM *vm)
     }
 
     MintResult r = capsule_mint_identity(dev, vm, full_name, username, email, phone,
-                                          (uint8_t *)0, (uint8_t *)0);
+                                          (uint8_t *)0, (uint8_t *)0,
+                                          0 /* not pre-checked -- keep the safety check */);
     switch (r) {
         case MINT_OK:
             console_println("MINT: identity minted");