fix(frank-archon): :" guard needs a space — :"${VAR:?}"` runs :204800

The TTM_TARGET_MIB guard I added on 1a6a78e was written `:"...` (no space), so
bash parsed the expansion as one word and executed `cmd :204800` as the
command `:204800`: exit 127 `command not found` on every start, before the
ttm gate ran. Caught on the deploy: the unit crash-looped 34 times in ~4 min
with exactly that journal line.

probe-frank-archon-kv.py now reads the slot count, window and KV dtype from the
deployed env on the host, so probe B exercises the capacity contract that is
actually live (4 x 200,000 today) instead of a hardcoded pair, and each probe's
marker starts with a unique word because show() scores the hit on that word.

scripts/probe-frank-archon-kv.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""probe-frank-archon-kv.py — verify the 2 x 200,000 KV contract on a LIVE
+"""probe-frank-archon-kv.py — verify the seqs x max-model-len KV contract on a
 frank-archon (radiance) service. Run it ON dankserver: it talks to
 127.0.0.1:7770 and builds its prompts from the repo checkout there.
 No scratch container, no mask: the service under test is the service.
@@ -10,10 +10,11 @@ Three probes, in increasing cost:
   A  decode at depth — one ~51k-token chat completion, 512 tokens, greedy.
      Reports the engine's own `timings` (prefill, decode, draft acceptance).
      The bench law applies: >=128 generated tokens, greedy, real text.
-  B  the capacity contract — TWO concurrent chats of ~197k prompt tokens
-     (~394k tokens resident) each carrying a unique marker at its head. Both
-     must answer their own marker. This is what a 2 x 200,000 endpoint owes:
-     two full-height conversations resident at once, exact retrieval in both.
+  B  the capacity contract — as many CONCURRENT chats of ~197k prompt tokens as
+     the deployed `FRANK_ARCHON_MAX_SEQS` (read from the repo env file on this
+     host), each carrying a unique marker at its head. All must answer their own
+     marker. This is what the endpoint owes: N full-height conversations
+     resident at once, exact retrieval in every one of them.
   C  prefix-cache restore — probe A's cold prompt again, so the disk tier has
      to give the blocks back (cache_n > 0, TTFT collapses).
 
@@ -114,23 +115,51 @@ def show(tag, j, wall, expect=None):
     print(line)
 
 
+def deployed_shape():
+    """The contract is the deployed env, not a constant: slot count and window
+    come from the checkout on this host, so the probe cannot drift from the
+    service it is testing (the 2026-10-13 shape is 4 x 200,000; before that
+    2 x 200,000, and the fp8 era 3 x 200,000)."""
+    shape = {}
+    with open(f"{REPO}/scripts/frank-archon.env") as fh:
+        for line in fh:
+            line = line.strip()
+            if line.startswith("FRANK_ARCHON_") and "=" in line:
+                key, _, val = line.partition("=")
+                shape[key] = val.strip().strip('"')
+    return (int(shape["FRANK_ARCHON_MAX_SEQS"]),
+            int(shape["FRANK_ARCHON_MAX_MODEL_LEN"]),
+            shape["FRANK_ARCHON_KV_DTYPE"])
+
+
 def main():
+    seqs, maxlen, dtype = deployed_shape()
+    print(f"shape: {seqs} x {maxlen:,} tokens, kv {dtype}")
     print("health:", json.dumps(get("/health")))
     print("models:", [m.get("id") for m in get("/v1/models").get("data", [])])
     deep = corpus(160_000)
     wide = corpus(1_100_000)
 
-    facts = {"B1": "cobalt-harbor-13", "B2": "quartz-meadow-42"}
-    bodies = {s: chat(wide, 646_000, s, f, 24) for s, f in facts.items()}
+    # 3.28 chars/token is the measured ratio of this corpus through the
+    # froggeric template (646,000 chars -> 196,919 tokens at the 2026-10-11
+    # deploy); 98.5 % of the window leaves the response room under the ceiling.
+    chars = int(0.985 * maxlen * 3.28)
+    # Each marker's FIRST hyphen-separated word is unique, because show()
+    # scores the hit on that word — a shared prefix would score every slot HIT
+    # on any answer that says the word.
+    words = ["cobalt", "quartz", "basalt", "ember", "willow", "cobweb", "flint"]
+    facts = {f"B{i+1}": f"{words[i % len(words)]}-flag-{(i + 1) * 137}"
+             for i in range(seqs)}
+    bodies = {s: chat(wide, chars, s, f, 24) for s, f in facts.items()}
     print(f"[B] {len(bodies['B1']['messages'][0]['content']):,} chars per "
-          f"request, x2 concurrent")
+          f"request, x{seqs} concurrent")
 
-    # A + C first (cheap), B last (the expensive pair).
+    # A + C first (cheap), B last (the expensive set).
     for tag, salt in (("A-cold", "A1-9137"), ):
         j, wall, _ = post(chat(deep, 140_000, salt, "zephyr-lantern-7", 512))
         show(tag, j, wall, "zephyr-lantern-7")
     t0 = time.time()
-    with concurrent.futures.ThreadPoolExecutor(max_workers=2) as ex:
+    with concurrent.futures.ThreadPoolExecutor(max_workers=seqs) as ex:
         futs = {s: ex.submit(post, b) for s, b in bodies.items()}
         for s, fut in futs.items():
             try:

scripts/serve-frank-archon.sh

@@ -62,7 +62,7 @@ set +a
 : "${FRANK_ARCHON_PREFIX_DISK_MIB:?FRANK_ARCHON_PREFIX_DISK_MIB must be set}"
 : "${FRANK_ARCHON_NGRAM_PLACEMENT:?FRANK_ARCHON_NGRAM_PLACEMENT must be set}"
 : "${FRANK_ARCHON_TTM_MIN_MIB:?FRANK_ARCHON_TTM_MIN_MIB must be set}"
-:"${FRANK_ARCHON_TTM_TARGET_MIB:?FRANK_ARCHON_TTM_TARGET_MIB must be set}"
+: "${FRANK_ARCHON_TTM_TARGET_MIB:?FRANK_ARCHON_TTM_TARGET_MIB must be set}"
 : "${FRANK_ARCHON_RAD_MIN_MIB:?FRANK_ARCHON_RAD_MIN_MIB must be set}"
 
 # The image gate is the digest-pinned ref itself: a name@sha256 ref exists