frank-large: correct the halogen payload contract to the Hub's truth

The first constants were wrong in three ways, found while resuming the
checkpoint (the file was COMPLETE; the manifest was not):
- checkpoint is 35,865,565,184 B / LFS sha256 274c3fc7... (not
  35,880,329,102 / 40874e7a...), 1352 tensors per the card;
- the tokenizer is a FLAT tokenizer/ DIRECTORY of 5 files mounted whole
  at /tokenizer (model-card docker-run parity; the engine's
  HALOGEN_TOKENIZER default is the directory) — there is no
  frank-large.tokenizer.gguf;
- plain git blobs (vocab/merges/jinja/config) carry no LFS oid, so the
  fetch script size-checks them and sha-verifies only the two LFS
  objects (checkpoint, tokenizer.json).

Gates flipped together (serve + deployer twins): tokenizer dir must be a
real directory and every named file a regular file, no symlinks (HF
snapshot links dangle in the mount). Fetch made idempotent: a file at
the published size skips the transfer (resuming it is a CDN 416 under
set -e). Seam rewritten to the same contract, 17/17.

tests/frank_large_unit.bats

@@ -55,7 +55,8 @@ STUB
 # stub agrees on and zero-byte artifacts passing the size gate.
 good_env() {
     : > "$TEST_TMP/empty.env"
-    touch "$TEST_TMP/qwen.hgn" "$TEST_TMP/tok.gguf"
+    touch "$TEST_TMP/qwen.hgn"
+    mkdir -p "$TEST_TMP/tokenizer" && touch "$TEST_TMP/tokenizer/tok.json"
     GOOD_ENV=(
         "FRANK_LARGE_ENV_FILE=$TEST_TMP/empty.env"
         "FRANK_LARGE_IMAGE=ghcr.io/peonist-ai/halogen@sha256:cafe"
@@ -68,7 +69,7 @@ good_env() {
         "FRANK_LARGE_MODEL_DIR=$TEST_TMP"
         "FRANK_LARGE_CHECKPOINT=qwen.hgn"
         "FRANK_LARGE_CHECKPOINT_BYTES=0"
-        "FRANK_LARGE_TOKENIZER=tok.gguf"
+        "FRANK_LARGE_TOKENIZER_FILES=tok.json"
         "HALOGEN_MODEL_ID=frank-large"
         "HALOGEN_SLOT_CTX=200700"
         "HALOGEN_KV_SLOTS=1"
@@ -83,6 +84,8 @@ good_env() {
     grep -qE '^FRANK_LARGE_PUBLISH=7770:8731$' "$ENV_FILE"
     grep -qE '^FRANK_LARGE_CHECKPOINT=.*\.hgn$' "$ENV_FILE"
     grep -qE '^FRANK_LARGE_CHECKPOINT_BYTES=[0-9]+$' "$ENV_FILE"
+    grep -qE '^FRANK_LARGE_CHECKPOINT_SHA256=[0-9a-f]{64}$' "$ENV_FILE"
+    grep -qE '^FRANK_LARGE_TOKENIZER_FILES="tokenizer\.json( [a-z_.]+)+"$' "$ENV_FILE"
     grep -qE '^HALOGEN_MODEL_ID=frank-large$' "$ENV_FILE"
     grep -qE '^HALOGEN_SLOT_CTX=[0-9]+$' "$ENV_FILE"
 }
@@ -156,14 +159,15 @@ good_env() {
     [[ "$output" == *"expected 42"* ]]
 }
 
-@test "the serve script refuses a symlinked tokenizer" {
+@test "the serve script refuses a symlinked tokenizer file" {
     # A HuggingFace cache snapshot's entries are symlinks into blobs/ and
-    # dangle inside the container mount.
+    # dangle inside the container mount — even when the directory itself
+    # is real.
     podman_stub
     good_env
-    ln -sf /nowhere/x "$TEST_TMP/link.gguf"
-    run env PATH="$TEST_TMP/bin:$PATH" "${GOOD_ENV[@]}" \
-        FRANK_LARGE_TOKENIZER=link.gguf "$SERVE"
+    rm "$TEST_TMP/tokenizer/tok.json"
+    ln -sf /nowhere/x "$TEST_TMP/tokenizer/tok.json"
+    run env PATH="$TEST_TMP/bin:$PATH" "${GOOD_ENV[@]}" "$SERVE"
     [ "$status" -ne 0 ]
     [[ "$output" == *"missing or a symlink"* ]]
 }
@@ -186,6 +190,7 @@ $(cat "$TEST_TMP/serve.log")"
     [[ "$output" == *"-e HALOGEN_DRAFTER=2"* ]]
     [[ "$output" == *"-e HALOGEN_CHECKPOINT=/models/qwen.hgn"* ]]
     [[ "$output" == *"--device $TEST_TMP/qwen.hgn"* ]]
+    [[ "$output" == *"$TEST_TMP/tokenizer:/tokenizer:ro"* ]]
     [[ "$output" == *"ghcr.io/peonist-ai/halogen@sha256:cafe"* ]]
     # The unit's restart policy is real because the script becomes
     # `podman wait`: the container's exit code is the service's exit.
@@ -218,9 +223,9 @@ $(cat "$TEST_TMP/serve.log")"
     grep -qF "LLM_LARGE_IMAGE=\"\${LLM_LARGE_IMAGE:-$img}\"" "$DEPLOYER"
     dir="$(sed -nE 's/^FRANK_LARGE_MODEL_DIR=(.*)$/\1/p' "$ENV_FILE")"
     ckpt="$(sed -nE 's/^FRANK_LARGE_CHECKPOINT=(.*)$/\1/p' "$ENV_FILE")"
-    tok="$(sed -nE 's/^FRANK_LARGE_TOKENIZER=(.*)$/\1/p' "$ENV_FILE")"
-    grep -qF "LLM_LARGE_CKPT=\"\${LLM_LARGE_CKPT:-$dir/$ckpt}\"" "$DEPLOYER"
-    grep -qF "LLM_LARGE_TOKENIZER=\"\${LLM_LARGE_TOKENIZER:-$dir/$tok}\"" "$DEPLOYER"
+    tokf="$(sed -nE 's/^FRANK_LARGE_TOKENIZER_FILES="(.*)"$/\1/p' "$ENV_FILE")"
+    grep -qF "LLM_LARGE_TOK_DIR=\"\${LLM_LARGE_TOK_DIR:-$dir/tokenizer}\"" "$DEPLOYER"
+    grep -qF "LLM_LARGE_TOK_FILES=\"\${LLM_LARGE_TOK_FILES:-$tokf}\"" "$DEPLOYER"
     bytes="$(sed -nE 's/^FRANK_LARGE_CHECKPOINT_BYTES=([0-9]+)$/\1/p' "$ENV_FILE")"
     grep -qF "LLM_LARGE_CKPT_BYTES=\"\${LLM_LARGE_CKPT_BYTES:-$bytes}\"" "$DEPLOYER"
 }