diff --git a/deploy/postgres/goose/00018_2026-09-12-outbox-notifications-stage-advance.sql b/deploy/postgres/goose/00018_2026-09-12-outbox-notifications-stage-advance.sql
new file mode 100644
index 00000000..e24c9831
--- /dev/null
+++ b/deploy/postgres/goose/00018_2026-09-12-outbox-notifications-stage-advance.sql
@@ -0,0 +1,58 @@
+-- +goose Up
+-- Phase 4: Outbox 事件、站内通知与阶段推进待办去重
+
+CREATE TABLE IF NOT EXISTS outbox_events (
+    id              BIGSERIAL PRIMARY KEY,
+    aggregate_type  TEXT NOT NULL,
+    aggregate_id    TEXT NOT NULL,
+    event_type      TEXT NOT NULL,
+    payload         JSONB NOT NULL DEFAULT '{}'::jsonb,
+    project_id      BIGINT REFERENCES projects(id) ON DELETE CASCADE,
+    created_at      TIMESTAMPTZ NOT NULL DEFAULT now(),
+    published_at    TIMESTAMPTZ
+);
+
+CREATE INDEX IF NOT EXISTS idx_outbox_unpublished ON outbox_events(created_at) WHERE published_at IS NULL;
+CREATE INDEX IF NOT EXISTS idx_outbox_project ON outbox_events(project_id, id DESC);
+
+CREATE TABLE IF NOT EXISTS notifications (
+    id          BIGSERIAL PRIMARY KEY,
+    user_id     BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    project_id  BIGINT REFERENCES projects(id) ON DELETE CASCADE,
+    event_id    BIGINT REFERENCES outbox_events(id) ON DELETE SET NULL,
+    type        TEXT NOT NULL,
+    title       TEXT NOT NULL,
+    body        TEXT NOT NULL DEFAULT '',
+    dedupe_key  TEXT NOT NULL,
+    status      TEXT NOT NULL DEFAULT 'unread',
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
+    read_at     TIMESTAMPTZ,
+    acted_at    TIMESTAMPTZ,
+    CONSTRAINT chk_notification_status CHECK (status IN ('unread', 'read', 'acted', 'dismissed')),
+    CONSTRAINT uq_notification_dedupe UNIQUE (user_id, dedupe_key)
+);
+
+CREATE INDEX IF NOT EXISTS idx_notifications_user ON notifications(user_id, id DESC);
+CREATE INDEX IF NOT EXISTS idx_notifications_project ON notifications(project_id, id DESC);
+
+CREATE TABLE IF NOT EXISTS stage_advance_requests (
+    id                   BIGSERIAL PRIMARY KEY,
+    stage_instance_id    BIGINT NOT NULL REFERENCES project_stage_instances(id) ON DELETE CASCADE,
+    workflow_instance_id BIGINT NOT NULL REFERENCES project_workflow_instances(id) ON DELETE CASCADE,
+    stage_key            TEXT NOT NULL,
+    readiness_revision   INT NOT NULL,
+    status               TEXT NOT NULL DEFAULT 'pending',
+    requested_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
+    decided_by           BIGINT REFERENCES users(id) ON DELETE SET NULL,
+    decided_at           TIMESTAMPTZ,
+    reason               TEXT NOT NULL DEFAULT '',
+    CONSTRAINT chk_sar_status CHECK (status IN ('pending', 'confirmed', 'superseded', 'cancelled')),
+    CONSTRAINT uq_sar_stage_revision UNIQUE (stage_instance_id, readiness_revision)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sar_instance ON stage_advance_requests(workflow_instance_id, status);
+
+-- +goose Down
+DROP TABLE IF EXISTS stage_advance_requests;
+DROP TABLE IF EXISTS notifications;
+DROP TABLE IF EXISTS outbox_events;