refact(comments): state the mechanism, not the incident

Every comment that invoked a 'law' (50 word-boundary sites across 28
tracked files) now states what is going on and why, in terms that
transfer to any project: gate twins drift until one side greenlights
what the other refuses; a tag re-points while a digest pins; a
restrictive engine behavior belongs to the runtime that imposed it and
must be re-tested, not inherited; a speculative head is tensors in the
file, not a flag; snapshot links dangle where the container resolves
them; exit 0 is a clean stop to systemd, so a self-exiting daemon on
on-failure goes dark reporting success. Event narratives and dates are
gone from these comments; the mechanics carry the argument.

Behavior-identical: bash -n, py_compile, yaml parse, full bats suite
408/408 green. One symbol rename rides along (stack script local
scale_law -> scale_contract, with its log text).

scripts/frank-dragoon.env

@@ -42,10 +42,11 @@
 #   form of the engine's default, so the seam test can pin the product.
 #   KV costs ~28 KiB/position (FLAGS.md) => 524,288 x 28 KiB = 14.0 GiB.
 #   HALOGEN_KV_SLOTS=2 restores the w4b-era shape on this box: the MTP
-#   drafter is NOT slot-locked on this engine (batching and speculation
-#   coexist — DFlash-era slots>1 law does NOT carry over; the card's own
-#   quickstart ships 2 slots WITH the head), so the second slot is
-#   concurrent capacity, not a speculation tax.
+#   drafter is NOT slot-locked on this engine. A "slots > 1 disables the
+#   drafter" restriction is a property of the engine generation that
+#   imposed it, not of speculation itself — batching and speculation
+#   coexist here, and the card's own quickstart ships 2 slots WITH the
+#   head — so the second slot is concurrent capacity, not a speculation tax.
 #   Memory ledger against the box's 121.2 GiB unified (the n-gram table is
 #   mmap'd page cache beside the checkpoint, not a pinned charge — the
 #   card's own quickstart arithmetic does not bill it):
@@ -88,9 +89,10 @@
 #     before. Kernel needs CONFIG_HSA_AMD_SVM (CachyOS ships it) and
 #     amdgpu.noretry=0 (check at deploy).
 
-# Image: digest-pinned (fetch law: tag pulls silently re-point; the digest
-# is what was qualified). 0.16.2 = the version the model card names as its
-# quickstart pin; RepoDigest captured at pull on 2026-10-06.
+# Image: digest-pinned, not tag-pinned — a tag can be re-pointed to a
+# build that was never qualified here, while the digest pins exactly the
+# build that was tested. 0.16.2 = the version the model card names as its
+# quickstart pin; the RepoDigest was captured at a pull of that tag.
 FRANK_DRAGOON_IMAGE=ghcr.io/peonist-ai/halogen-flash-server@sha256:0c61bf84ac22308a53f5d1ca6b86806702d7039e5ebc51cae4c66621b92fe04a
 # Container identity: kept from the 27B era (unit ExecStop names it).
 FRANK_DRAGOON_CONTAINER=frank-dragoon-halogen