Standardize orchestrator child-script execution and logging

Every orchestrator invoked its children differently — four near-duplicate
run_job() copies, a differently-shaped run_watchdog(), or plain inline bash
calls, each with its own take on path resolution, pass/fail naming, and
dry-run threading. Extracted one shared run_orch_child() into common.sh so
there's a single place to fix or extend this behavior going forward.

Along the way: watchdog_orchestrator.sh and monthly_maintenance.sh were
checking $VERBOSE, a variable nothing in the codebase ever assigns, so --log
silently did nothing beyond basic logging on those two. Fixed to
$ENABLE_LOGGING. watchdog_orchestrator.sh and array_started.sh had no
trailing exit, so their exit codes reflected whatever the last command
happened to return rather than actual success/failure. transcode_management.sh
had no failure notification and no summary at all. Also made
transcode_management.sh's two-script pipeline config-driven
(TRANSCODE_MANAGEMENT_SCRIPTS in master.conf) instead of hardcoded, for room
to extend it later without editing the orchestrator itself.

common.sh

@@ -1537,6 +1537,64 @@ _release_rsync_on_exit() {
     fi
 }
 
+# ==============================================================================================
+# ── ORCHESTRATOR CHILD EXECUTION ──────────────────────────────────────────────────────────────
+# ==============================================================================================
+# Shared child-script runner for Orchestrators/*.sh. Replaces the run_job()/run_watchdog()
+# copies that used to be hand-duplicated (with small inconsistencies) into each orchestrator —
+# one implementation now, one place to fix a bug or extend behavior (e.g. per-child logging).
+#
+# Usage — caller declares its own tracking arrays before the loop:
+#   JOB_PASS=()
+#   JOB_FAIL=()
+#   for entry in "${SOME_SCRIPTS[@]}"; do
+#       run_orch_child "$entry"
+#   done
+#
+# $entry is "relative/path.sh [extra args...]" — the same format every master.conf
+# script-list array already uses. Resolved against $ECOSYSTEM_ROOT, which the caller
+# must set before calling this (the absolute repo root — "$(cd "$SCRIPT_DIR/.." && pwd)").
+#
+# --dry-run / --log are threaded down automatically from $DRY_RUN / $ENABLE_LOGGING —
+# never $VERBOSE, which nothing in this codebase ever assigns.
+
+run_orch_child() {
+    local entry="$1"
+    local script_args script_path script_name label extra_args run_args
+
+    read -r -a script_args <<< "$entry"
+    script_path="$ECOSYSTEM_ROOT/${script_args[0]}"
+    script_name=$(basename "${script_args[0]}")
+    extra_args=("${script_args[@]:1}")
+    label="$script_name"
+    [[ -n "${extra_args[*]}" ]] && label="$script_name ${extra_args[*]}"
+
+    if [[ ! -f "$script_path" ]]; then
+        error "$script_name — not found at $script_path"
+        JOB_FAIL+=("$label")
+        return 1
+    fi
+    [[ ! -x "$script_path" ]] && chmod +x "$script_path"
+
+    run_args=("${extra_args[@]}")
+    [[ "$DRY_RUN"        == true ]] && run_args+=("--dry-run")
+    [[ "$ENABLE_LOGGING" == true ]] && run_args+=("--log")
+
+    local _start _ec
+    _start=$(date +%s)
+    log "Running: $label"
+    if bash "$script_path" "${run_args[@]}"; then
+        log "$script_name — done in $(format_duration $(( $(date +%s) - _start )))"
+        JOB_PASS+=("$label")
+        return 0
+    else
+        _ec=$?
+        error "$label — failed (exit $_ec, $(format_duration $(( $(date +%s) - _start ))))"
+        JOB_FAIL+=("$label")
+        return 1
+    fi
+}
+
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