§H.12 step 4: Hera registers as session zero; punch list to checkboxes

Rewired stadium_birth_hera() to admit unpinned then register through
session_register()/session_set_pinned() instead of setting
STADIUM_FLAG_PIN directly on the candidate header. Self-referential
parent (vm_uuid_hera(), vm_uuid_hera()), matching capsule_run.h's
parent_vm_id == vm_id root convention. Soft-fail, non-fatal, if
session_register() fails -- Hera's actual Stadium admission is what the
patron-zero invariant is about. Wired session_boot_init() into
kernel_main.c right after stadium_boot_init(), before stadium_birth_hera().

Also converted §H.12's punch list from bold "DONE" markers to this
document's established - [ ]/- [x] checkbox convention (already used
throughout §A), for consistency.

Verified 3-arch boot to ok> (amd64/aarch64/riscv64), no soft-fail message
on any arch, Hermes/Artemis births unaffected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

FABRIC-3.md

@@ -3941,80 +3941,90 @@ identity work lands") — wiring real identities into them is part of this refac
 work, not new invention.
 
 **Phase 1 — Session struct + pin-authority choke point**
-1. **DONE 2026-09-03.** `include/starkernel/session.h`: `Session{vm_id (VMUuid), pinned (int),
+- [x] **1. DONE 2026-09-03.** `include/starkernel/session.h`: `Session{vm_id (VMUuid), pinned
-   parent (VMUuid), name (fixed buffer, `SESSION_NAME_BUF`=64), identity (VMIdentity,
+  (int), parent (VMUuid), name (fixed buffer, `SESSION_NAME_BUF`=64), identity (VMIdentity,
-   embedded)}`. Type only, no logic. No callers yet, so this acceptance run only confirms the
+  embedded)}`. Type only, no logic. No callers yet, so this acceptance run only confirms the
-   header itself is syntactically clean and doesn't break the build. Verified 3-arch boot to
+  header itself is syntactically clean and doesn't break the build. Verified 3-arch boot to
-   `ok>` (amd64/aarch64/riscv64).
+  `ok>` (amd64/aarch64/riscv64).
-2. **DONE 2026-09-03, one deviation from the original wording.** `src/starkernel/vm/session.c`
+- [x] **2. DONE 2026-09-03, one deviation from the original wording.**
-   + `session_boot_init()`/`session_find(VMUuid)`/`session_register(...)`. Not a fixed-size
+  `src/starkernel/vm/session.c` + `session_boot_init()`/`session_find(VMUuid)`/
-   array as originally written here — found `stadium.c`'s own `StadiumVMQuota` table had
+  `session_register(...)`. Not a fixed-size array as originally written here — found
-   already been moved off a fixed array to a `kmalloc`'d-at-boot, budget-sized one (same
+  `stadium.c`'s own `StadiumVMQuota` table had already been moved off a fixed array to a
-   "population isn't knowable in advance" reasoning), so `session.c` mirrors that current
+  `kmalloc`'d-at-boot, budget-sized one (same "population isn't knowable in advance"
-   precedent instead: `session_boot_init()` sizes the slot table from `stadium_max_vm_count()`,
+  reasoning), so `session.c` mirrors that current precedent instead: `session_boot_init()`
-   must run after `stadium_boot_init()`. Added `session.c` to `Makefile.starkernel`'s explicit
+  sizes the slot table from `stadium_max_vm_count()`, must run after `stadium_boot_init()`.
-   `LOADER_EXTRA_SRCS`/`KERNEL_EXTRA_SRCS` list (not a wildcard build). No callers yet.
+  Added `session.c` to `Makefile.starkernel`'s explicit `LOADER_EXTRA_SRCS`/
-   Verified 3-arch boot to `ok>`.
+  `KERNEL_EXTRA_SRCS` list (not a wildcard build). No callers yet. Verified 3-arch boot to
-3. **DONE 2026-09-03, one addition found necessary.** `session_set_pinned()`/
+  `ok>`.
-   `session_is_pinned()` implemented — the pin-authority choke point (H.2/H.10).
+- [x] **3. DONE 2026-09-03, one addition found necessary.** `session_set_pinned()`/
-   `session_is_pinned()` answers from `Session.pinned` directly (the authoritative copy, no
+  `session_is_pinned()` implemented — the pin-authority choke point (H.2/H.10).
-   Stadium re-derivation); `session_set_pinned()` writes both `Session.pinned` and the
+  `session_is_pinned()` answers from `Session.pinned` directly (the authoritative copy, no
-   mirrored `STADIUM_FLAG_PIN` bit on the session's own patron header, so Stadium's own
+  Stadium re-derivation); `session_set_pinned()` writes both `Session.pinned` and the
-   internal eviction/admission logic (which must stay self-contained, no call back into
+  mirrored `STADIUM_FLAG_PIN` bit on the session's own patron header, so Stadium's own
-   session.c) keeps seeing a correct bit. **Addition**: `Session` needed a `stadium_cell`
+  internal eviction/admission logic (which must stay self-contained, no call back into
-   field (index into `stadium_cells()`) that wasn't in the original §H.2 field list — the
+  session.c) keeps seeing a correct bit. **Addition**: `Session` needed a `stadium_cell`
-   choke point can't reach the right patron header without it. Necessary plumbing, not a new
+  field (index into `stadium_cells()`) that wasn't in the original §H.2 field list — the
-   session-level concept, so not treated as reopening §H.2's design. Also moved
+  choke point can't reach the right patron header without it. Necessary plumbing, not a new
-   `STADIUM_FLAG_PIN`'s `#define` from a `stadium.c`-private constant to `stadium.h` (public)
+  session-level concept, so not treated as reopening §H.2's design. Also moved
-   so `session.c` can reference it without duplicating the definition. Verified 3-arch boot to
+  `STADIUM_FLAG_PIN`'s `#define` from a `stadium.c`-private constant to `stadium.h` (public)
-   `ok>`.
+  so `session.c` can reference it without duplicating the definition. Verified 3-arch boot to
-4. Rewire `stadium_birth_hera()` to register through `session_register()`/
+  `ok>`.
-   `session_set_pinned()` instead of setting `STADIUM_FLAG_PIN` directly — Hera becomes
+- [x] **4. DONE 2026-09-03.** Rewired `stadium_birth_hera()` to admit unpinned then register
-   session zero.
+  through `session_register(vm_uuid_hera(), vm_uuid_hera(), "Hera")` (self-referential
+  parent, matching `capsule_run.h`'s `parent_vm_id == vm_id` root convention) +
+  `session_set_pinned(vm_uuid_hera(), 1)` — Hera is session zero. `stadium_admit()` confirmed
+  to have no admission-time-special pin handling (just copies the candidate header), so
+  admit-unpinned-then-pin-after is safe. Soft-fail (logged, non-fatal) if `session_register()`
+  fails — Hera's actual Stadium admission already succeeded and is what the patron-zero
+  invariant is about. Wired `session_boot_init()` into `kernel_main.c` right after
+  `stadium_boot_init()`, before `stadium_birth_hera()`. Verified 3-arch boot to `ok>`, no
+  soft-fail message logged on any arch (registration succeeded), Hermes/Artemis births
+  unaffected.
 
 **Phase 2 — Pin Hermes/Artemis (Correction 1 above)**
-5. In `capsule_birth.c`'s existing generic admission block, add a name check ("Hera"/
+- [ ] **5.** In `capsule_birth.c`'s existing generic admission block, add a name check
-   "Hermes"/"Artemis" → pinned, everything else → unpinned) routed through
+  ("Hera"/"Hermes"/"Artemis" → pinned, everything else → unpinned) routed through
-   `session_register()`/`session_set_pinned()`.
+  `session_register()`/`session_set_pinned()`.
-6. Confirm (boot-log/diagnostic) Hermes and Artemis now admit pinned; ordinary births still
+- [ ] **6.** Confirm (boot-log/diagnostic) Hermes and Artemis now admit pinned; ordinary
-   admit unpinned.
+  births still admit unpinned.
 
 **Phase 3 — Session fields wired at birth**
-7. Populate `Session.parent` from the birthing VM's `stadium_vm_id`.
+- [ ] **7.** Populate `Session.parent` from the birthing VM's `stadium_vm_id`.
-8. Populate `Session.name` from the capsule's own name string (already available at this
+- [ ] **8.** Populate `Session.name` from the capsule's own name string (already available at
-   point in `capsule_birth.c`).
+  this point in `capsule_birth.c`).
-9. Confirm `Session.identity` defaults to `installed=0` correctly (no behavior change
+- [ ] **9.** Confirm `Session.identity` defaults to `installed=0` correctly (no behavior
-   expected yet).
+  change expected yet).
 
 **Phase 4 — Creator-ceiling enforcement (H.3, birth-time snapshot)**
-10. `dictionary_snapshot_acl_from_parent(child, parent)`: for each word also present in the
+- [ ] **10.** `dictionary_snapshot_acl_from_parent(child, parent)`: for each word also present
-    parent's dictionary, copy `acl_allow`/`acl_mode`/`acl_pinned`/`acl_ttl` into the child's
+  in the parent's dictionary, copy `acl_allow`/`acl_mode`/`acl_pinned`/`acl_ttl` into the
-    matching entry.
+  child's matching entry.
-11. Call it once, right after a child's dictionary finishes loading in `capsule_birth.c`.
+- [ ] **11.** Call it once, right after a child's dictionary finishes loading in
+  `capsule_birth.c`.
 
 **Phase 5 — `BMAPFMT` (§F.4/§H.6, independent, can run any time)**
-12. Edit `blk_meta_t` in `include/block_subsystem.h`: replace the old 4 ownership fields with
+- [ ] **12.** Edit `blk_meta_t` in `include/block_subsystem.h`: replace the old 4 ownership
-    `owner_fp[8]`/`acl_allow`/`acl_ttl` (u32)/`acl_reserved[3]`/`reserved_future`. Verify
+  fields with `owner_fp[8]`/`acl_allow`/`acl_ttl` (u32)/`acl_reserved[3]`/`reserved_future`.
-    size/offsets with `offsetof`/`sizeof`, not by hand (see the `blk_volume_meta_t` padding-bug
+  Verify size/offsets with `offsetof`/`sizeof`, not by hand (see the `blk_volume_meta_t`
-    lesson, [[project_phase8_milestone6_complete]]).
+  padding-bug lesson, [[project_phase8_milestone6_complete]]).
-13. Define the three `flags` bit constants (`CLAIMED`=0/`MIGRATING`=1/`STALE`=2).
+- [ ] **13.** Define the three `flags` bit constants (`CLAIMED`=0/`MIGRATING`=1/`STALE`=2).
-14. Add C get/set accessors for the new fields in `block_subsystem.c`.
+- [ ] **14.** Add C get/set accessors for the new fields in `block_subsystem.c`.
-15. Add FORTH wrappers (`BLK-ACL-ALLOW@`/`!`, `BLK-ACL-TTL@`/`!`, `BLK-OWNER@`).
+- [ ] **15.** Add FORTH wrappers (`BLK-ACL-ALLOW@`/`!`, `BLK-ACL-TTL@`/`!`, `BLK-OWNER@`).
-16. Add a new policy capsule (mirroring `ACL.4th`) with a real fast-deny check on top — no
+- [ ] **16.** Add a new policy capsule (mirroring `ACL.4th`) with a real fast-deny check on
-    stub, per this project's standing "no stubs or TODOs, ever" rule (§C).
+  top — no stub, per this project's standing "no stubs or TODOs, ever" rule (§C).
 
 **Phase 6 — Zuse eligibility list (H.5)**
-17. Extend the metadata-fence record format with a new growable `owner_pubkey[32]`-list
+- [ ] **17.** Extend the metadata-fence record format with a new growable
-    record type.
+  `owner_pubkey[32]`-list record type.
-18. Implement read/add/membership-check functions in C.
+- [ ] **18.** Implement read/add/membership-check functions in C.
-19. Add a Zuse-only FORTH word to add an entry, gated by `zuse_session`.
+- [ ] **19.** Add a Zuse-only FORTH word to add an entry, gated by `zuse_session`.
 
 **Phase 7 — Message card gate + `ELEVATE-REQUEST` (H.8)**
-20. Add the initiator-only ACL gate at `CH-REQUEST`'s entry point (default-permissive
+- [ ] **20.** Add the initiator-only ACL gate at `CH-REQUEST`'s entry point
-    baseline, real hook point established).
+  (default-permissive baseline, real hook point established).
-21. Define `ELEVATE-REQUEST` and a minimal real handler checking the eligibility list,
+- [ ] **21.** Define `ELEVATE-REQUEST` and a minimal real handler checking the eligibility
-    granting via `ACL-ALLOW!`/`ACL-TTL!` on match.
+  list, granting via `ACL-ALLOW!`/`ACL-TTL!` on match.
-22. Add the FORTH entrypoint a session actually calls to send one.
+- [ ] **22.** Add the FORTH entrypoint a session actually calls to send one.
 
 **Excluded, per H.11's deferred items 10–11**: VM card multi-owner support, live-console
 `sudo`-style elevation, pre-signed capability tickets.

capsules/BLOCK_MAP.md

@@ -1,5 +1,5 @@
 # Capsule Block Manifest — Auto-generated
-<!-- Generated by mkcapsule --manifest  2026-09-03T10:08:29Z -->
+<!-- Generated by mkcapsule --manifest  2026-09-03T10:14:23Z -->
 <!-- DO NOT EDIT — re-run mkcapsule --manifest to refresh.  -->
 <!-- Hand-written justifications and immutability notes live  -->
 <!-- in MANIFEST.md alongside this auto-generated index.      -->

src/starkernel/kernel_main.c

@@ -58,6 +58,7 @@ EFI_RUNTIME_SERVICES *g_sk_runtime_services = NULL;
 #include "starkernel/vm/stadium.h"
 #include "starkernel/vm/stadium_words.h"
 #include "starkernel/vm/stadium_blocks.h"
+#include "starkernel/session.h"
 #include "starkernel/capsule_generated.h"
 #include "starkernel/capsule_loader.h"
 #include "starkernel/capsule_birth.h"  /* capsule_birth_mama, capsule_find_mama_init */
@@ -512,6 +513,14 @@ static void kernel_main_deep(BootInfo *boot_info) {
      * yet, so a failed allocation logs and boot continues. */
     (void)stadium_boot_init();
 
+    /* Session: boot-time allocation (FABRIC-3.md §H.12 step 4), sized from
+     * stadium_max_vm_count() so it must run after stadium_boot_init() above
+     * and before the first session is registered (stadium_birth_hera()
+     * below registers Hera as session zero). Soft failure, same reasoning
+     * as stadium_boot_init() -- stadium_birth_hera() itself soft-fails a
+     * failed session_register() rather than treating it as fatal. */
+    (void)session_boot_init();
+
     /* item 4.1, FABRIC.md item 3.6/§17.7: actually enforce "Hera is patron
      * zero" before anything else can land on cell 0 via the free list, then
      * bring up the word layer's map. Both must happen before the first word

src/starkernel/vm/stadium.c

@@ -41,6 +41,7 @@
 #include "starkernel/q48_16.h" /* Q48_ONE -- item 4.1's reservoir starts each VM's quota at 1.0 */
 #include "vm.h" /* VM_MEMORY_SIZE -- the per-VM footprint stadium_max_vm_count() budgets against */
 #include "block_subsystem.h" /* blk_flush() -- STADIUM_BEHAVIOUR_MIGRATE's real write-back action */
+#include "starkernel/session.h" /* session_register()/session_set_pinned() -- FABRIC-3.md §H.12 step 4 */
 
 static StadiumCell *stadium_cell_array   = (StadiumCell *)0;
 static uint8_t      *stadium_bitmap       = (uint8_t *)0;
@@ -637,6 +638,17 @@ uint64_t stadium_resident_sum(VMUuid vm_id) {
  * item-3.1 discriminator bitmap -- if cell 0 already reads as resident,
  * something already birthed her (or, if it isn't actually Hera, something
  * else already claimed cell 0 -- either way this must not clobber it).
+ *
+ * FABRIC-3.md §H.12 step 4: pinning no longer happens by setting
+ * STADIUM_FLAG_PIN on the candidate before admission -- session.c's
+ * session_set_pinned() is now the sole choke point for that bit (§H.10).
+ * Hera is admitted unpinned, then registered as session zero
+ * (self-referential parent, matching capsule_run.h's parent_vm_id ==
+ * vm_id convention for the root) and pinned through the session layer.
+ * Session registration/pinning is soft-fail (logged, not fatal) -- Hera's
+ * actual Stadium admission above already succeeded and is what the
+ * patron-zero invariant is about; session.c not yet being initialized
+ * must not break that.
  */
 int stadium_birth_hera(void) {
     StadiumPatronHeader candidate;
@@ -656,7 +668,7 @@ int stadium_birth_hera(void) {
     candidate.link      = STADIUM_LINK_NONE;
     candidate.contains  = STADIUM_CONTAINS_NONE;
     candidate.mass      = 1;
-    candidate.flags     = STADIUM_FLAG_PIN;
+    candidate.flags     = 0;
     candidate.behaviour = (uint8_t)STADIUM_BEHAVIOUR_COOL;
 
     idx = stadium_admit(vm_uuid_hera(), &candidate);
@@ -664,6 +676,17 @@ int stadium_birth_hera(void) {
     if (idx != STADIUM_HERA_CELL_INDEX) {
         sk_hal_panic("Stadium: birth_hera did not land on cell 0 -- patron-zero invariant broken");
     }
+
+    {
+        Session *s = session_register(vm_uuid_hera(), vm_uuid_hera(), "Hera");
+        if (s) {
+            s->stadium_cell = idx;
+            session_set_pinned(vm_uuid_hera(), 1);
+        } else {
+            console_println("Stadium: session_register failed for Hera (session.c not yet initialized?)");
+        }
+    }
+
     return 0;
 }