feat: ship loose-offline dbsync (validate, agent push, LWW audit)

Add UUID/FK channel checks, agent whitelist/push APIs, bindings, super-admin LWW audit with rollback, reconcile rate limits, and sync docs. Default customers stay opt-in; company conflict UI is removed.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/internal/dbsync/rollback_test.go

@@ -0,0 +1,54 @@
+package dbsync
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestRollbackRejectsNonApplied(t *testing.T) {
+	dir := t.TempDir()
+	st, err := NewFileStore(filepath.Join(dir, "dbsync"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	o := LwwOverride{
+		ID:        "ov1",
+		TenantID:  1,
+		ChannelID: "ch1",
+		Table:     "orders",
+		RowPK:     "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee",
+		Outcome:   OutcomeKept,
+		CreatedAt: time.Now().UTC(),
+	}
+	if err := st.AddLwwOverride(o); err != nil {
+		t.Fatal(err)
+	}
+	_, err = RollbackLwwOverride(context.Background(), st, "ov1")
+	if err == nil {
+		t.Fatal("expected reject kept_target")
+	}
+}
+
+func TestGetLwwOverride(t *testing.T) {
+	dir := t.TempDir()
+	st, err := NewFileStore(filepath.Join(dir, "dbsync"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	o := LwwOverride{
+		ID:       "ov2",
+		TenantID: 1,
+		Table:    "t",
+		RowPK:    "pk",
+		Outcome:  OutcomeApplied,
+	}
+	if err := st.AddLwwOverride(o); err != nil {
+		t.Fatal(err)
+	}
+	got, err := st.GetLwwOverride("ov2")
+	if err != nil || got.Table != "t" {
+		t.Fatalf("got=%+v err=%v", got, err)
+	}
+}