fix: move EXTRACT_DIR + WORK_DIR off tmpfs onto disk-backed bind mount

rc=137 OOM kill triaged on whp02 darkside import. dmesg confirmed:
  memory: usage 2097100kB, limit 2097152kB, failcnt 132
  oom_kill_process ... task=bash uid=999

Root cause: extract.sh untars the cpmove into EXTRACT_DIR which was
/tmp/extract — a tmpfs mount (RAM-backed). The container's
--memory 2g cgroup ceiling counts tmpfs writes against RSS, so the
3 GB cpmove decompressing into tmpfs hit the limit at ~7s into tar
and the kernel killed the bash process running extract.sh.

Fix is structural, not a memory bump: the disk-backed bind mount
at /host/sanitized (mapped to /var/lib/whp/cpanel-importer-extract
on host) has effectively unlimited capacity and doesn't count against
the cgroup memory limit. Moving the working dirs there sidesteps the
OOM class entirely.

Layout change:
  EXTRACT_DIR  /tmp/extract           -> $SANITIZED_DIR/extract-work
  WORK_DIR     /tmp/sanitized         -> $SANITIZED_DIR/work

Two ripple changes:
  - The old rsync_out stage cross-filesystem-copied ~10 GB from tmpfs
    to /host/sanitized/<id>/extracted. That's now a same-filesystem
    `mv` (constant-time rename) since extract-work IS already inside
    /host/sanitized/<id>/. Stage renamed to finalize_layout for
    clarity; pre-existing wipe of extracted/ + mysql/ guards against
    partial-run residue.
  - The stripped-symlinks actions sidecar moved to /tmp explicitly
    (entrypoint.sh passes the 4th arg to extract.sh) so finalize's
    rename doesn't (a) carry a dotfile into the cleaned tree the
    panel imports and (b) move it out from under write_report's read.

Also fixes the unrelated-but-cosmetic freshclam warning by cd'ing to
/var/lib/clamav (the configured DatabaseDirectory, tmpfs writable)
before invoking freshclam in a subshell. The "Can't create
freshclam.dat in /opt/whp" errors were because /opt/whp is the
container WORKDIR which lives on the read-only rootfs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/entrypoint.sh

@@ -85,9 +85,22 @@ SANITIZED_DIR="/host/sanitized/$IMPORT_ID"
 mkdir -p "$QUARANTINE_DIR" "$SANITIZED_DIR" \
     || die "cannot create quarantine/sanitized output dirs (are the bind mounts RW?)"
 
-# Container-internal scratch space (mounted as tmpfs by the panel).
-EXTRACT_DIR="/tmp/extract"
-WORK_DIR="/tmp/sanitized"
+# Working scratch lives inside the disk-backed bind mount, NOT under /tmp.
+# /tmp is mounted as tmpfs (RAM-backed) by the panel for fast small-file
+# scratch (per-stage reports, exclude lists). Putting the multi-GB cpmove
+# extract there blew the container's --memory 2g cgroup ceiling (tmpfs
+# writes count against cgroup RSS), surfaced as rc=137 OOM kills mid-tar.
+#
+# Layout:
+#   EXTRACT_DIR  $SANITIZED_DIR/extract-work — tar untars here. After
+#                scan-files quarantines bad files, this is the cleaned
+#                tree. Renamed to $SANITIZED_DIR/extracted at the end of
+#                the run so the panel can find it at the expected path.
+#   WORK_DIR     $SANITIZED_DIR/work          — scan-dbs writes cleaned
+#                SQL dumps here; folded into $SANITIZED_DIR/mysql at the
+#                end of the run.
+EXTRACT_DIR="$SANITIZED_DIR/extract-work"
+WORK_DIR="$SANITIZED_DIR/work"
 mkdir -p "$EXTRACT_DIR" "$WORK_DIR/mysql"
 
 # --- refresh ClamAV signatures --------------------------------------------
@@ -95,9 +108,15 @@ mkdir -p "$EXTRACT_DIR" "$WORK_DIR/mysql"
 STAGE="freshclam"
 if [[ "$CLAMAV_REFRESH" == "true" ]]; then
     log "refreshing ClamAV signatures (freshclam)"
+    # freshclam writes freshclam.dat to its CWD; the container's WORKDIR
+    # is /opt/whp which lives on the read-only rootfs, so freshclam errors
+    # with "Can't create freshclam.dat in /opt/whp" before it ever reaches
+    # the database directory. Subshell + cd to the tmpfs at /var/lib/clamav
+    # (the DatabaseDirectory configured in /etc/freshclam.conf) keeps the
+    # entrypoint's CWD intact for later stages.
     # freshclam is allowed to fail (e.g., container has no outbound net);
     # we proceed with the baseline rules from build time + log a warning.
-    if ! freshclam --no-warnings >/tmp/freshclam.log 2>&1; then
+    if ! ( cd /var/lib/clamav && freshclam --no-warnings >/tmp/freshclam.log 2>&1 ); then
         log "WARN: freshclam failed; proceeding with build-time signature DB"
         tail -20 /tmp/freshclam.log || true
     fi
@@ -109,7 +128,11 @@ fi
 
 STAGE="extract"
 log "stage: extract"
-if ! /scripts/extract.sh "$IMPORT_BACKUP_FILE" "$EXTRACT_DIR" "$IMPORT_USERNAME"; then
+# 4th arg pins the stripped-symlinks actions sidecar to /tmp (not inside
+# $EXTRACT_DIR) so finalize_layout's mv doesn't carry an importer dotfile
+# into the cleaned tree and so write_report can read it after the rename.
+STRIPPED_SYMLINKS_FILE="/tmp/stripped-symlinks.json"
+if ! /scripts/extract.sh "$IMPORT_BACKUP_FILE" "$EXTRACT_DIR" "$IMPORT_USERNAME" "$STRIPPED_SYMLINKS_FILE"; then
     die "extract.sh failed; see stderr above"
 fi
 
@@ -137,29 +160,31 @@ php /scripts/scan-dbs.php \
     --username "$IMPORT_USERNAME" \
     || die "scan-dbs.php failed; see stderr above"
 
-# --- rsync cleaned tree to /host/sanitized --------------------------------
+# --- finalize cleaned tree into /host/sanitized/<id>/ ---------------------
 
-STAGE="rsync_out"
-log "stage: rsync_out"
-# Copy the (now-cleaned) extracted tree to the sanitized output. We exclude
-# files that scan-files.php quarantined — they are NOT present in the
-# extract dir anymore (the scanner moved them), so this is the cleaned
-# tree by construction.
-rsync -a --no-owner --no-group --no-perms --chmod=Du=rwx,Dg=rx,Do=,Fu=rw,Fg=r,Fo= \
-      "$EXTRACT_DIR"/ "$SANITIZED_DIR/extracted/" \
-    || die "rsync to sanitized dir failed"
-
-# Then drop the cleaned .sql files in place too.
-rsync -a --no-owner --no-group --no-perms --chmod=Du=rwx,Dg=rx,Do=,Fu=rw,Fg=r,Fo= \
-      "$WORK_DIR/mysql"/ "$SANITIZED_DIR/mysql/" \
-    || die "rsync of cleaned .sql files failed"
+STAGE="finalize_layout"
+log "stage: finalize_layout"
+# Both EXTRACT_DIR and WORK_DIR already live INSIDE $SANITIZED_DIR (the
+# bind-mounted disk-backed output root), so we don't need to cross-filesystem
+# rsync 10GB+ of cleaned files. A same-filesystem `mv` is constant-time
+# (just a rename) — turns what used to be a multi-minute rsync into a
+# fraction of a second.
+#
+# Cleanup posture: if a previous run partially populated `extracted/` or
+# `mysql/`, we wipe them first so the rename can't fail with EEXIST. The
+# container's --read-only rootfs makes accidentally removing the wrong
+# path impossible — these are under the per-import bind mount only.
+rm -rf "$SANITIZED_DIR/extracted" "$SANITIZED_DIR/mysql"
+mv "$EXTRACT_DIR"    "$SANITIZED_DIR/extracted" || die "finalize: rename extract-work failed"
+mv "$WORK_DIR/mysql" "$SANITIZED_DIR/mysql"     || die "finalize: rename work/mysql failed"
+# Tidy up the now-empty WORK_DIR shell.
+rmdir "$WORK_DIR" 2>/dev/null || true
 
 # --- merge per-stage reports into the final report.json -------------------
 
 STAGE="write_report"
 log "stage: write_report"
 DURATION=$(( $(date -u +%s) - START_TS ))
-STRIPPED_SYMLINKS_FILE="$EXTRACT_DIR/.cpanel-importer-stripped-symlinks.json"
 php -r '
 $importId       = $argv[1];
 $duration       = (int) $argv[2];