diff --git a/.woodpecker/ci.yml b/.woodpecker/ci.yml
index cb3244d3..482e4a65 100644
--- a/.woodpecker/ci.yml
+++ b/.woodpecker/ci.yml
@@ -98,6 +98,12 @@ steps:
       DATABASE_URL: postgresql://mosaic:mosaic@ci-postgres:5432/mosaic
     commands:
       - *enable_pnpm
+      # openssl (#912) is the wake HMAC signer: the digest H1/H2, beacon B12,
+      # and install I8 legs hard-require it in CI. It is baked into ci-base via
+      # Dockerfile.ci, but ci-base only rebuilds on push-to-main/tag — this
+      # `apk add` guarantees openssl is present on PR pipelines too (and is a
+      # fast no-op once the rebuilt image already ships it).
+      - apk add --no-cache openssl
       # postgresql-client (pg_isready) is baked into ci-base.
       # Wait up to 60s for CI postgres to be ready; fail fast if it never comes up.
       - |
diff --git a/Dockerfile.ci b/Dockerfile.ci
index c5b0be7b..aed28067 100644
--- a/Dockerfile.ci
+++ b/Dockerfile.ci
@@ -25,7 +25,10 @@ FROM node:24-alpine
 # postgresql-client used by the test step's pg_isready readiness probe. `bash`,
 # `git`, and `jq` are baked here too — framework shell tests and the shipped
 # Codex review wrappers require them without per-run installation in ci.yml.
-RUN apk add --no-cache python3 make g++ postgresql-client bash git jq
+# `openssl` (#912) is the non-circular HMAC signer for the wake trust layer:
+# the digest H1/H2, beacon B12, and install I8 legs hard-require it in CI so the
+# §4 G6 evidence comes from an actually-run HMAC leg, not a skipped one.
+RUN apk add --no-cache python3 make g++ postgresql-client bash git jq openssl
 
 # Pin pnpm to the repo's packageManager version via corepack.
 RUN corepack enable && corepack prepare pnpm@10.6.2 --activate
diff --git a/packages/mosaic/framework/tools/wake/digest.sh b/packages/mosaic/framework/tools/wake/digest.sh
index 26bb4a6e..beab0d31 100755
--- a/packages/mosaic/framework/tools/wake/digest.sh
+++ b/packages/mosaic/framework/tools/wake/digest.sh
@@ -108,16 +108,37 @@ EOF
 # _scrub_ctrl (stdin) — strip ANSI escape sequences, Unicode bidi controls,
 # zero-width characters, and C0/C1 control bytes. Byte-exact under LC_ALL=C so a
 # multibyte control sequence cannot slip through a locale-dependent class.
+#
+# PORTABILITY (#912): the byte patterns are LITERAL bytes (materialized via
+# `printf %b`), NOT GNU-sed `\xNN` hex escapes. `\xNN` is a GNU-sed extension;
+# BusyBox sed (the Alpine/musl CI runner, running as root) REJECTS a `\xNN`
+# character range with "bad regex ... Invalid character range", which aborted
+# the whole sed and silently VOIDED the scrub in CI — the digest suite's D1/D4/
+# D5/D6 all failed only in the Woodpecker runner because every scrubbed value
+# collapsed to empty. Literal bytes match identically under GNU sed (glibc dev)
+# and BusyBox sed (Alpine CI): a wake digest must render byte-for-byte the same
+# regardless of the runner's sed implementation. LC_ALL=C keeps every match
+# byte-exact (no locale-dependent multibyte class).
 _scrub_ctrl() {
+  local ESC p280 p281 aa ae a6 a9 x8b x8f a0 bom alm
+  ESC="$(printf '%b' '\x1b')"     # U+001B ESC
+  p280="$(printf '%b' '\xe2\x80')" # UTF-8 lead bytes for U+2000..U+203F
+  p281="$(printf '%b' '\xe2\x81')" # UTF-8 lead bytes for U+2040..U+207F
+  aa="$(printf '%b' '\xaa')"; ae="$(printf '%b' '\xae')"   # U+202A..U+202E bidi
+  a6="$(printf '%b' '\xa6')"; a9="$(printf '%b' '\xa9')"   # U+2066..U+2069 isolates
+  x8b="$(printf '%b' '\x8b')"; x8f="$(printf '%b' '\x8f')" # U+200B..U+200F zero-width
+  a0="$(printf '%b' '\xa0')"                               # U+2060 word joiner
+  bom="$(printf '%b' '\xef\xbb\xbf')"                      # U+FEFF BOM/ZWNBSP
+  alm="$(printf '%b' '\xd8\x9c')"                          # U+061C arabic letter mark
   LC_ALL=C sed -E \
-    -e 's/\x1b\[[0-9;?]*[ -/]*[@-~]//g' \
-    -e 's/\x1b[@-Z\\-_]//g' \
-    -e 's/\xe2\x80[\xaa-\xae]//g' \
-    -e 's/\xe2\x81[\xa6-\xa9]//g' \
-    -e 's/\xe2\x80[\x8b-\x8f]//g' \
-    -e 's/\xe2\x81\xa0//g' \
-    -e 's/\xef\xbb\xbf//g' \
-    -e 's/\xd8\x9c//g' |
+    -e 's/'"$ESC"'\[[0-9;?]*[ -/]*[@-~]//g' \
+    -e 's/'"$ESC"'[@-Z\\-_]//g' \
+    -e 's/'"$p280"'['"$aa"'-'"$ae"']//g' \
+    -e 's/'"$p281"'['"$a6"'-'"$a9"']//g' \
+    -e 's/'"$p280"'['"$x8b"'-'"$x8f"']//g' \
+    -e 's/'"$p281$a0"'//g' \
+    -e 's/'"$bom"'//g' \
+    -e 's/'"$alm"'//g' |
     LC_ALL=C tr -d '\000-\010\013\014\016-\037\177'
 }
 
diff --git a/packages/mosaic/framework/tools/wake/manifest.txt b/packages/mosaic/framework/tools/wake/manifest.txt
index f5445f56..f26bc522 100644
--- a/packages/mosaic/framework/tools/wake/manifest.txt
+++ b/packages/mosaic/framework/tools/wake/manifest.txt
@@ -45,7 +45,19 @@
 #              pointer carries a usable (soft) locator instead of rendering
 #              empty. Display-only: the ACTIONABLE-tier hard-locator FAIL-LOUD
 #              gate (_has_hard_locator, exit 4) is unchanged.
-#   0.6.3  #920 digest.sh drain-quarantine + reconciler-enumeration render tier
+#   0.6.3  #912 digest.sh scrub PORTABILITY (no contract change): _scrub_ctrl's
+#              control/bidi/zero-width byte patterns are now LITERAL bytes (via
+#              printf %b) instead of GNU-sed `\xNN` hex escapes. BusyBox sed (the
+#              Alpine/musl CI runner, running as root) rejects a `\xNN` character
+#              range, which aborted the whole scrub sed and silently VOIDED the
+#              scrub in CI — collapsing every scrubbed value to empty and failing
+#              the digest suite's D1/D4/D5/D6 only in the Woodpecker runner. The
+#              scrub now renders byte-identically under GNU sed (glibc dev) and
+#              BusyBox sed (Alpine CI). The two-tier trust, exit-4 hard-locator
+#              FAIL-LOUD, and the secret-scrub/SHA-preservation contract are all
+#              unchanged — this makes the existing scrub deterministic across
+#              runners, it does not weaken it.
+#   0.6.4  #920 digest.sh drain-quarantine + reconciler-enumeration render tier
 #              (live wake-pilot finding #6, BLOCKING). (a) PER-ENTRY
 #              QUARANTINE: a render-refused ACTIONABLE entry (no §2.1 hard
 #              locator) is now DEAD-LETTERED to $STATE_DIR/dead-letter.jsonl +
@@ -62,9 +74,9 @@
 #              only. reconcile.sh's STORE class is UNCHANGED (non-coalescing), so
 #              distinct enumerations never collapse (§2.3/T2/G3-R6 intact); the
 #              rejected class=digest alternative would have silently coalesced
-#              them. store.sh and reconcile.sh are UNCHANGED by 0.6.3.
+#              them. store.sh and reconcile.sh are UNCHANGED by 0.6.4.
 component=wake
-version=0.6.3
+version=0.6.4
 
 # Watch-list schema this component consumes, and the INCLUSIVE range of
 # schema_version values it supports. A wake-watch-list.json whose schema_version
diff --git a/packages/mosaic/framework/tools/wake/test-wake-beacon.sh b/packages/mosaic/framework/tools/wake/test-wake-beacon.sh
index b87dbe68..c707acee 100755
--- a/packages/mosaic/framework/tools/wake/test-wake-beacon.sh
+++ b/packages/mosaic/framework/tools/wake/test-wake-beacon.sh
@@ -296,8 +296,15 @@ echo "== B11: staleness from monitor ingested_ts -> a far-future emit_ts STILL g
 ) && ok
 
 echo "== B12: HMAC-verify at record -> a spoofed (bad-sig) beacon is REJECTED =="
+# #912: hard-require openssl in CI (Woodpecker sets CI=woodpecker) so the beacon
+# HMAC-verify leg is actually exercised; keep the skip for openssl-less local dev.
 if ! command -v openssl >/dev/null 2>&1; then
-  echo "SKIP: openssl not available" >&2
+  if [ -n "${CI:-}" ]; then
+    echo "  FAIL: B12 requires openssl in CI (#912) but it is not on PATH — the CI image must provide it" >&2
+    echo "x" >>"$FAILFILE"
+  else
+    echo "SKIP: openssl not available (local dev; CI hard-requires it)" >&2
+  fi
 else
 (
   H="$(fresh_home b12)"
diff --git a/packages/mosaic/framework/tools/wake/test-wake-digest-hmac.sh b/packages/mosaic/framework/tools/wake/test-wake-digest-hmac.sh
index 20997c7d..40208181 100755
--- a/packages/mosaic/framework/tools/wake/test-wake-digest-hmac.sh
+++ b/packages/mosaic/framework/tools/wake/test-wake-digest-hmac.sh
@@ -43,11 +43,20 @@ command -v jq >/dev/null 2>&1 || {
   echo "SKIP: jq not available" >&2
   exit 0
 }
-# NOTE: whole-suite openssl-skip retained; unmasking D1-D6 to run in CI is tracked in #912 (they currently fail under the CI env).
-command -v openssl >/dev/null 2>&1 || {
-  echo "SKIP: openssl not available" >&2
+# openssl gates the HMAC legs (H1/H2). #912: the wake trust layer MUST be
+# exercised in real CI, so when running under CI (Woodpecker sets CI=woodpecker)
+# openssl is HARD-REQUIRED — a missing openssl fails the suite LOUD rather than
+# silently skipping the signer (the §4 G6 evidence must come from an
+# actually-run HMAC leg, not a skipped one). In an openssl-less LOCAL DEV env
+# the whole suite still skips so `pnpm test` stays runnable without openssl.
+if ! command -v openssl >/dev/null 2>&1; then
+  if [ -n "${CI:-}" ]; then
+    echo "FATAL (#912): openssl is REQUIRED in CI to exercise the wake digest/HMAC trust layer, but is not on PATH. The CI image must provide openssl (see .woodpecker/ci-image.yml)." >&2
+    exit 1
+  fi
+  echo "SKIP: openssl not available (local dev; CI hard-requires it)" >&2
   exit 0
-}
+fi
 
 TMP_ROOT="$(mktemp -d)"
 trap 'rm -rf "$TMP_ROOT"' EXIT
@@ -222,10 +231,26 @@ echo "== D4: SCRUB — secret-canary + ANSI/bidi/zero-width in source free-text
   # ANSI escape / CSI must be gone.
   printf '%s' "$out" | LC_ALL=C grep -q "$(printf '\x1b')" && fail_msg "D4: ANSI ESC survived the scrub"
   # bidi/zero-width/BOM UTF-8 sequences must be gone.
-  printf '%s' "$out" | LC_ALL=C grep -qP '\xe2\x80[\x8b-\x8f\xaa-\xae]|\xef\xbb\xbf' &&
+  # #912: patterns are LITERAL bytes + `grep -E`, NOT PCRE `grep -P`. BusyBox
+  # grep (Alpine/musl CI) has no `-P` — a `grep -qP` there errors
+  # ("unrecognized option: P"), returns non-zero, and the `&&` silently skips
+  # the assertion, so the scrub was NEVER checked in CI. Literal-byte ranges
+  # under `grep -E` + LC_ALL=C match identically on BusyBox and GNU grep.
+  # Two DISJOINT byte ranges: U+200B..U+200F (E2 80 8B..8F, zero-width) and
+  # U+202A..U+202E (E2 80 AA..AE, bidi). NOT a single 8B..AE range — that would
+  # wrongly flag legitimate E2 80 xx punctuation in between, e.g. U+2014 EM DASH
+  # (E2 80 94) which the digest body uses.
+  _b280="$(printf '%b' '\xe2\x80')"
+  _b8b="$(printf '%b' '\x8b')"; _b8f="$(printf '%b' '\x8f')"
+  _baa="$(printf '%b' '\xaa')"; _bae="$(printf '%b' '\xae')"
+  _bbom="$(printf '%b' '\xef\xbb\xbf')"
+  printf '%s' "$out" | LC_ALL=C grep -qE "${_b280}[${_b8b}-${_b8f}${_baa}-${_bae}]|${_bbom}" &&
     fail_msg "D4: bidi/zero-width/BOM survived the scrub"
   # C0 control bytes (except tab/newline) must be gone.
-  printf '%s' "$out" | LC_ALL=C grep -qP '[\x00-\x08\x0e-\x1f\x7f]' && fail_msg "D4: a C0 control byte survived the scrub"
+  _c00="$(printf '%b' '\x01')"; _c08="$(printf '%b' '\x08')"
+  _c0e="$(printf '%b' '\x0e')"; _c1f="$(printf '%b' '\x1f')"; _c7f="$(printf '%b' '\x7f')"
+  printf '%s' "$out" | LC_ALL=C grep -qE "[${_c00}-${_c08}${_c0e}-${_c1f}${_c7f}]" &&
+    fail_msg "D4: a C0 control byte survived the scrub"
   # Secret canaries must be redacted, never inlined.
   printf '%s' "$out" | grep -q 'ghp_0123456789' && fail_msg "D4: GitHub-token canary LEAKED into the digest"
   printf '%s' "$out" | grep -q 'AKIAIOSFODNN7EXAMPLE' && fail_msg "D4: AWS-key canary LEAKED into the digest"
diff --git a/packages/mosaic/framework/tools/wake/test-wake-install.sh b/packages/mosaic/framework/tools/wake/test-wake-install.sh
index 839b438b..3d89e4ef 100755
--- a/packages/mosaic/framework/tools/wake/test-wake-install.sh
+++ b/packages/mosaic/framework/tools/wake/test-wake-install.sh
@@ -219,8 +219,15 @@ echo "== I7: ingested_ts staleness — a far-future emit_ts still goes stale (re
 ) && ok
 
 echo "== I8: beacon HMAC-verify at record — a spoofed (bad-sig) beacon is REJECTED =="
+# #912: hard-require openssl in CI (Woodpecker sets CI=woodpecker) so the install
+# beacon-sign leg is actually exercised; keep the skip for openssl-less local dev.
 if ! command -v openssl >/dev/null 2>&1; then
-  echo "SKIP: openssl not available" >&2
+  if [ -n "${CI:-}" ]; then
+    echo "  FAIL: I8 requires openssl in CI (#912) but it is not on PATH — the CI image must provide it" >&2
+    echo "x" >>"$FAILFILE"
+  else
+    echo "SKIP: openssl not available (local dev; CI hard-requires it)" >&2
+  fi
 else
 (
   H="$(fresh i8)"