feat(frank-archon): four decode slots over a >=700k-token KV pool

Frank's order: 4 slots, a 700k pool, round UP if the resolver cannot land it
exactly. The cache target is MAX_SEQS x MAX_MODEL_LEN, so the demand is
800,000 fp8 tokens; the resolver funds ~91-93 % of demand (three boots of
evidence on the endpoint page), which clears 700k, and the VRAM has to come
from the expert plane -- which has to go somewhere, so HOST_POOL_MIB moves with
it. expert_vram_floor (core/place/planner.cpp:100-104) is exactly
plane + 2 units - host_room, and the live boot ledger pins that plane at 67.60
GiB a rank (23.73 GiB floor at 44,928 of room), so 49,152 drops the floor to
19.61 GiB and leaves the cache ~6.9 GiB: enough for the whole target, with the
leftover returned to the experts.

Costs, both real: pinned host RAM 87.75 -> 96.0 GiB (the pool is pinned once per
rank) and ~3.2 GiB a card of expert residency, read over the x8 Gen5 link when
the router picks a host-resident expert. The boot ledger's vram_kv line is the
referee; if it comes back under 700,000 tokens HOST_POOL_MIB goes up 1024 and
this redeploys.

TTM_MIN_MIB 150,000 -> 162,000 for the new pin ledger (2 x pool + PLE 48,824 +
prefix 8,192 + MNBT 2,048 + the auto checkpoint store, now 40 slots of 112 MiB =
161,848 MiB), and the bats ledger guard now counts the checkpoint store because
it grows with the slot count. The two env-value assertions in that seam are
bumped with the values they guard.

tests/frank_archon_unit.bats

@@ -145,7 +145,7 @@ nosudo_bin() {
     # (torch.compile query_start_loc constraint, 2026-10-02); radiance booted
     # seqs 2 in the fp8-native era and the 2026-10-06 sweep had seqs 2 and 3
     # tied inside the +-3% noise floor — slots buy concurrency, not speed.
-    grep -q '^FRANK_ARCHON_MAX_SEQS=2$' "$ENV_FILE"
+    grep -q '^FRANK_ARCHON_MAX_SEQS=4$' "$ENV_FILE"
     grep -q '^FRANK_ARCHON_TP=2$' "$ENV_FILE"
     grep -q '^FRANK_ARCHON_TP_WIRE=wht6$' "$ENV_FILE"
     grep -q '^FRANK_ARCHON_SPEC_TOKENS=2$' "$ENV_FILE"
@@ -158,7 +158,7 @@ nosudo_bin() {
     # so the pool's token count is a boot-ledger line — verified live by the
     # capacity leg of scripts/probe-frank-archon-kv.py at every cutover.
     grep -q '^FRANK_ARCHON_PLACEMENT=expert_tiered$' "$ENV_FILE"
-    grep -q '^FRANK_ARCHON_HOST_POOL_MIB=44928$' "$ENV_FILE"
+    grep -q '^FRANK_ARCHON_HOST_POOL_MIB=49152$' "$ENV_FILE"
     grep -q '^FRANK_ARCHON_KV_DTYPE=fp8$' "$ENV_FILE"
     grep -q '^FRANK_ARCHON_NGRAM_PLACEMENT=ram$' "$ENV_FILE"
     # Prefix cache: pinned host RAM only (the disk tier was removed), and the
@@ -177,8 +177,11 @@ nosudo_bin() {
     [ "$ttmt" -gt "$ttmm" ]
     pool=$(awk -F= '/^FRANK_ARCHON_HOST_POOL_MIB=/{print $2}' "$ENV_FILE")
     ph=$(awk -F= '/^FRANK_ARCHON_PREFIX_CACHE_MIB=/{print $2}' "$ENV_FILE")
-    # 2 pools + PLE 47.7 GiB (48,824 MiB) + prefix host, rounded up.
-    ledger=$(( 2 * pool + 48824 + ph + 2048 ))
+    # 2 pools + PLE 47.7 GiB (48,824 MiB) + prefix host + MNBT + the auto
+    # checkpoint store (MAX_SEQS x 10 slots of 112 MiB -- the store is pinned host
+    # memory too, and it grows with the slot count).
+    seqs=$(awk -F= '/^FRANK_ARCHON_MAX_SEQS=/{print $2}' "$ENV_FILE")
+    ledger=$(( 2 * pool + 48824 + ph + 2048 + seqs * 10 * 112 ))
     [ "$ttmm" -ge "$ledger" ]
     # The .rad size floor is positive (a truncated convert must fail fast).
     grep -q '^FRANK_ARCHON_RAD_MIN_MIB=' "$ENV_FILE"