feat(mail): adapt M365 ETL loop for OO+Gmail bots.

Default compose mail-sync to onlyoffice,gmail every 300s with import on new
mail; gate full --rebuild behind MAIL_SYNC_INDEX. Fix mail-build stage order
and add bin/stack/start-mail-sync.

bin/docker-entrypoint

@@ -5,7 +5,7 @@
 #   serve | search | watch
 # Index image (Python write path, compose profile `index`):
 #   index | extract | audit | search (deprecated python wrapper)
-#   mail-sync [N]   pull loop: sync -> import -> index every N s (default 10)
+#   mail-sync [N]   ETL loop: sync -> import; optional index (default 300s)
 #
 # Usage comment starts at line 2 (self-describing convention).
 set -euo pipefail
@@ -36,20 +36,23 @@ case "$CMD" in
 	extract) exec "$KB_PY" /app/bin/facts/extract "$@" ;;
 	audit) exec "$KB_PY" /app/bin/facts/audit "$@" ;;
 	mail-sync)
-		# loop: pull mail (M365/OnlyOffice/Gmail) every N s, convert to md,
-		# rebuild the brain index. Index only when something new arrived.
-		interval="${1:-10}"
-		[ "$interval" -gt 0 ] 2>/dev/null || interval=10
-		: "${MAIL_SYNC_ENV:=/secret/m365.env}"
-		: "${MAIL_SYNC_SRC:=m365}"
+		# ETL: pull mail, convert to md when new>0. Full --rebuild is opt-in
+		# (MAIL_SYNC_INDEX=1) — ~29k leaf rebuild is minutes, not a 10s loop.
+		interval="${1:-300}"
+		[ "$interval" -gt 0 ] 2>/dev/null || interval=300
+		: "${MAIL_SYNC_ENV:=/secret/mail.env}"
+		: "${MAIL_SYNC_SRC:=onlyoffice,gmail}"
 		: "${MAIL_SYNC_OUT:=/app/var/mail}"
+		: "${MAIL_SYNC_INDEX:=0}"
 		while true; do
-			out="$("/app/bin/mail-sync" --source "$MAIL_SYNC_SRC" --env "$MAIL_SYNC_ENV" --out "$MAIL_SYNC_OUT" 2>&1)"
+			out="$("/app/bin/mail-sync" --source "$MAIL_SYNC_SRC" --env "$MAIL_SYNC_ENV" --out "$MAIL_SYNC_OUT" 2>&1)" || true
 			echo "$out"
 			new="$(printf '%s\n' "$out" | sed -n 's/.*new=\([0-9]*\).*/\1/p' | tail -1)"
 			if [ -n "$new" ] && [ "$new" -gt 0 ] 2>/dev/null; then
 				"$KB_PY" /app/bin/mail/import --from-raw "$MAIL_SYNC_OUT" 2>&1 | tail -1
-				"$KB_PY" /app/bin/kb/index --rebuild --with-mail 2>&1 | tail -1
+				if [ "$MAIL_SYNC_INDEX" = "1" ]; then
+					"$KB_PY" /app/bin/kb/index --rebuild --with-mail 2>&1 | tail -1
+				fi
 			fi
 			sleep "$interval"
 		done

bin/stack/lib.sh

@@ -143,12 +143,17 @@ ensure_picoclaw() {
 	wait_health "$PICOCLAW_URL/health" || stack_die "picoclaw health failed at $PICOCLAW_URL/health"
 }
 
+mail_sync_running() {
+	compose ps --status running --services 2>/dev/null | grep -qx mail-sync
+}
+
 stack_status() {
-	local bh=down mcp=down ph=down present=false
+	local bh=down mcp=down ph=down present=false ms=down
 	health_ok "$BRAIN_URL/health" && bh=ok
 	mcp_ok && mcp=ok
 	reasoner_has_model && present=true
 	health_ok "$PICOCLAW_URL/health" && ph=ok
+	mail_sync_running && ms=ok
 	cat <<EOF
 brain:
   url: $BRAIN_URL
@@ -161,6 +166,9 @@ reasoner:
 picoclaw:
   url: $PICOCLAW_URL
   health: $ph
+mail_sync:
+  service: mail-sync
+  running: $ms
 EOF
 }
 
@@ -168,6 +176,11 @@ stack_start() {
 	ensure_brain
 }
 
+stack_start_mail_sync() {
+	echo "mail-sync: compose up (ETL sync→import; index only if MAIL_SYNC_INDEX=1)" >&2
+	compose up -d mail-sync
+}
+
 stack_attach_agent() {
 	local opts=()
 	if [[ -t 0 && -t 1 ]]; then
@@ -230,6 +243,6 @@ stack_stop() {
 		return 0
 		;;
 	esac
-	echo "stack: stop brain brain-mcp reasoner picoclaw (volumes kept)" >&2
-	compose --profile picoclaw --profile reasoner stop picoclaw brain-mcp reasoner brain
+	echo "stack: stop brain brain-mcp reasoner picoclaw mail-sync (volumes kept)" >&2
+	compose --profile picoclaw --profile reasoner stop picoclaw brain-mcp reasoner brain mail-sync
 }

bin/stack/start-mail-sync

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# bin/stack/start-mail-sync - compose up mail-sync ETL (sync → import; optional index).
+#
+#   bin/stack/start-mail-sync
+#
+# Default: onlyoffice,gmail every 300s into kb-var. Full --rebuild only if
+# MAIL_SYNC_INDEX=1 in compose/env. Secrets: ~/.config/brain/mail.env +
+# ~/.gmail-mcp (mounted). Does not start brain/picoclaw.
+set -euo pipefail
+
+STACK_DIR="$(CDPATH= cd -- "$(dirname "$0")" && pwd)"
+# shellcheck source=lib.sh
+source "$STACK_DIR/lib.sh"
+case "${1:-}" in
+-h | --help)
+	stack_usage "$0"
+	exit 0
+	;;
+esac
+stack_start_mail_sync "$@"
+stack_status

bin/stack/stop

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# bin/stack/stop - stop compose brain / brain-mcp / reasoner / picoclaw.
+# bin/stack/stop - stop compose brain / brain-mcp / reasoner / picoclaw / mail-sync.
 #
 #   bin/stack/stop
 #

bin/tools/test_stack.py

@@ -9,7 +9,7 @@ import unittest
 from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[2]
-METHODS = ("start", "start-assistant", "stop", "status")
+METHODS = ("start", "start-assistant", "start-mail-sync", "stop", "status")
 
 
 class StackLayoutTest(unittest.TestCase):
@@ -32,8 +32,10 @@ class StackLayoutTest(unittest.TestCase):
         lib = (ROOT / "bin" / "stack" / "lib.sh").read_text()
         self.assertIn("stack_start", lib)
         self.assertIn("stack_start_assistant", lib)
+        self.assertIn("stack_start_mail_sync", lib)
         self.assertIn("stack_stop", lib)
         self.assertIn("stack_status", lib)
+        self.assertIn("mail-sync", lib)
         self.assertIn("qwen3.5:9b", lib)
         self.assertIn("picoclaw agent", lib)
         self.assertIn("--no-deps", lib)
@@ -49,6 +51,16 @@ class StackLayoutTest(unittest.TestCase):
         self.assertNotIn("stack_start_assistant", start)
         self.assertNotIn("picoclaw agent", start)
 
+    def test_start_mail_sync_is_etl_only(self) -> None:
+        src = (ROOT / "bin" / "stack" / "start-mail-sync").read_text()
+        self.assertIn("stack_start_mail_sync", src)
+        self.assertNotIn("stack_start_assistant", src)
+        ep = (ROOT / "bin" / "docker-entrypoint").read_text()
+        self.assertIn('MAIL_SYNC_SRC:=onlyoffice,gmail', ep)
+        self.assertIn('MAIL_SYNC_INDEX:=0', ep)
+        self.assertIn('interval="${1:-300}"', ep)
+        self.assertIn('MAIL_SYNC_INDEX" = "1"', ep)
+
     def test_start_assistant_attaches_agent(self) -> None:
         src = (ROOT / "bin" / "stack" / "start-assistant").read_text()
         self.assertIn("stack_start_assistant", src)
@@ -151,7 +163,10 @@ exit 0
                 check=False,
             )
             self.assertEqual(r.returncode, 0, r.stderr)
-            self.assertFalse(log.exists(), "healthy brain must not docker compose up")
+            if log.exists():
+                logged = log.read_text()
+                self.assertNotIn("up -d", logged, "healthy brain must not docker compose up")
+                self.assertIn("ps", logged)  # status probes mail-sync via compose ps
 
     def test_start_ups_brain_when_unhealthy(self) -> None:
         with tempfile.TemporaryDirectory() as raw:
@@ -190,7 +205,7 @@ exit 0
             logged = log.read_text()
             self.assertIn("stop", logged)
             self.assertNotIn(" down", logged)
-            for svc in ("brain", "brain-mcp", "reasoner", "picoclaw"):
+            for svc in ("brain", "brain-mcp", "reasoner", "picoclaw", "mail-sync"):
                 self.assertIn(svc, logged)
 
     def test_start_assistant_no_attach_starts_picoclaw(self) -> None: