chore: declare GreptimeDB Enterprise License for enterprise-gated sources (#8364)

* chore: declare GreptimeDB Enterprise License for enterprise-gated sources

The `enterprise`-feature-gated sources (triggers, mito2 extension) were
excluded from the Apache-2.0 header check but carried no license of their
own. Declare a separate GreptimeDB Enterprise License and enforce it.

- Add LICENSE-ENTERPRISE (open-core split; core stays Apache-2.0).
- Add an Enterprise License header to each enterprise source file.
- Add licenserc-enterprise.toml and a second hawkeye step in CI to enforce
  the Enterprise header on exactly those files.
- Cross-reference the two complementary file lists; document the layout in
  licenses/README.md and the README License section.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

* chore: reference per-customer Enterprise Agreement instead of a terms URL

There is no public enterprise-terms page; each customer signs an individually
negotiated agreement. Point the license at a "separate written commercial
agreement with GrepTime Inc." and direct readers to the existing contact page.

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

---------

Signed-off-by: Dennis Zhuang <killme2008@gmail.com>

src/sql/src/parsers/alter_parser/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use snafu::{ResultExt, ensure};
 use sqlparser::ast::Ident;
 use sqlparser::parser::Parser;

src/sql/src/parsers/create_parser/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use std::time::Duration;
 
 use snafu::{OptionExt, ResultExt, ensure};

src/sql/src/parsers/show_parser/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use snafu::{ResultExt, ensure};
 
 use crate::error::{self, Result};

src/sql/src/statements/alter/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use std::fmt::{Display, Formatter};
 
 use serde::Serialize;

src/sql/src/statements/create/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use std::fmt::{Display, Formatter};
 use std::ops::ControlFlow;
 use std::time::Duration;

src/sql/src/statements/drop/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use std::fmt::Display;
 
 use serde::Serialize;

src/sql/src/statements/show/trigger.rs

@@ -1,3 +1,14 @@
+// Copyright 2023-2026 GrepTime Inc.
+//
+// This file is part of the GreptimeDB Enterprise Edition and is licensed under
+// the GreptimeDB Enterprise License. You may not use this file except in
+// compliance with that license. A copy of the license is available at the root
+// of this repository in the file LICENSE-ENTERPRISE.
+//
+// Unless required by applicable law or agreed to in writing, this software is
+// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied.
+
 use std::fmt::{self, Display};
 
 use serde::Serialize;