§H.12 step 17: zuse_eligibility_list.h -- eligibility-list record format

Growable owner_pubkey[32]-list devblock type for the metadata fence,
one slot over from zuse_genesis_marker_t (§H.5 Phase 6). Type only,
no read/add/check logic yet.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QgooKd5hJNtTYqB6CyK5f9

FABRIC-3.md

@@ -4098,8 +4098,19 @@ work, not new invention.
   FORTH wrappers, and a real policy word all landed and verified.
 
 **Phase 6 — Zuse eligibility list (H.5)**
-- [ ] **17.** Extend the metadata-fence record format with a new growable
-  `owner_pubkey[32]`-list record type.
+- [x] **17. DONE 2026-09-03.** `include/starkernel/zuse_eligibility_list.h`:
+  `zuse_eligibility_devblock_t` (magic/version/count/`next_devblock_from_top`/127×
+  `owner_pubkey[32]` entries/CRC-64, padded to exactly one 4 KiB devblock, `_Static_assert`
+  verified) — same raw-devblock convention as `zuse_genesis_marker_t`. Lives in the same
+  top-of-device metadata fence one slot over: head devblock at
+  `ZUSE_ELIGIBILITY_LIST_HEAD_DEVBLOCK`=1 (genesis marker owns 0). Growable via a singly-
+  linked chain of devblocks (`next_devblock_from_top`, `ZUSE_ELIGIBILITY_LIST_NO_NEXT` =
+  sentinel) drawn from the already-reserved 128-devblock `BLK_META_FENCE_INIT` budget — no
+  fence-growth logic needed yet, only 2 of 128 devblocks are spoken for. Type only, no
+  read/add/check logic yet (that's item 18) and no callers, so this acceptance run only
+  confirms the header is syntactically clean (verified via a standalone `gcc -fsyntax-only`
+  compile, and via the struct-size static assert) and doesn't break the build. Verified
+  3-arch boot to `ok>` (amd64/aarch64/riscv64).
 - [ ] **18.** Implement read/add/membership-check functions in C.
 - [ ] **19.** Add a Zuse-only FORTH word to add an entry, gated by `zuse_session`.