Disarm on offboard every sync gate onboard arms, with the same helper, so the two are one operation in both directions

common.sh

@@ -939,9 +939,53 @@ is_own_conf_file() {
     [[ "${1,,}" == "${MY_ID,,}.conf" ]]
 }
 
+# ── Set a boolean toggle in master.conf, in place ─────────────────────────────────────────────
+# Booleans only. The value pattern stops at whitespace, so a quoted value containing spaces would
+# be truncated — every gate this sets is true/false and nothing else should use it.
+#
+# Preserves what the line already looks like: leading indent, the existing quoting style, and the
+# column the trailing comment sits in. master.conf is hand-aligned and read by a person; an edit
+# that reflows a line makes a diff that looks bigger than the change actually is.
+#
+# Prefer this over update_master_conf() for toggles. That one rewrites the entire line as
+# "    KEY=VALUE", which drops the trailing comment — run it over the four sync gates and
+# master.conf loses the notes explaining what each tier does.
+#
+# Lives here rather than in partnership_onboard.sh because onboard arming a gate and offboard
+# disarming the same gate must be the same operation in both directions.
+# Usage: set_conf_bool "$key" "true"|"false" "$master_conf_path"
+set_conf_bool() {
+    local key="$1" val="$2" file="$3" cur pad spaces quoted gap
+    if ! grep -qE "^[[:space:]]*${key}=" "$file"; then
+        warn "  ${key} is not in master.conf — skipped (add it to the template first)"
+        return 1
+    fi
+    cur=$(grep -E "^[[:space:]]*${key}=" "$file" | head -1 | sed -E "s|^[[:space:]]*${key}=||; s|[[:space:]]*#.*$||")
+    quoted=""; [[ "$cur" == \"*\" ]] && quoted='"'
+    cur="${cur//\"/}"
+    [[ "$cur" == "$val" ]] && { echo "  ${key} already ${val}"; return 0; }
+
+    # Rewrite the whole gap rather than padding on top of the existing one. Adding
+    # (len(old) - len(new)) spaces in front of the gap that is already there holds the column for
+    # one edit and drifts on the next: false→true pads +1, true→false pads 0 but keeps that space,
+    # so every arm/disarm cycle pushes the comment one column right. An onboard and offboard pair
+    # is exactly that cycle, and master.conf is hand-aligned.
+    pad=0
+    if grep -qE "^[[:space:]]*${key}=[^#]*#" "$file"; then
+        # Existing run of spaces between the value and the #
+        gap=$(grep -E "^[[:space:]]*${key}=" "$file" | head -1 \
+              | sed -E "s|^[[:space:]]*${key}=[^#[:space:]]*||; s|#.*$||")
+        pad=$(( ${#gap} + ${#cur} - ${#val} ))
+        (( pad < 1 )) && pad=1
+    fi
+    spaces=$(printf '%*s' "$pad" '')
+    sed -i -E "s|^([[:space:]]*)${key}=[^#[:space:]]*[[:space:]]*(#.*)?$|\1${key}=${quoted}${val}${quoted}${spaces}\2|" "$file"
+    echo "  ${key}: ${cur} → ${val}"
+}
+
 # Sets key=value in a flat state file (setup.db style) — updates in place if the
-# key exists, appends if not. No indentation handling — for master.conf use
-# partnership_manager.sh's update_master_conf() instead.
+# key exists, appends if not. No indentation handling — for master.conf toggles use
+# set_conf_bool() above.
 # Usage: set_state_var "$state_file" "$key" "$value"
 set_state_var() {
     local file="$1" key="$2" value="$3"