chore(core): standardize SPDX copyright headers

Add SPDX copyright and license headers to source, test, migration,
template, and static files throughout the project.

Include the maintainer email in copyright notices and fill in the BSD
license copyright holder.

7 files changed, 42 insertions, 0 deletions

diff --git a/webmentions_ssg/templates/base.html b/webmentions_ssg/templates/base.html
index eb11b8e..1275391 100644
--- a/webmentions_ssg/templates/base.html
+++ b/webmentions_ssg/templates/base.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% from "bootstrap5/utils.html" import render_messages %}
 <!DOCTYPE html>
 <html lang="en" data-bs-theme="dark">
diff --git a/webmentions_ssg/templates/includes/confirmation_modal.html b/webmentions_ssg/templates/includes/confirmation_modal.html
index ff9bd06..5c0a5a1 100644
--- a/webmentions_ssg/templates/includes/confirmation_modal.html
+++ b/webmentions_ssg/templates/includes/confirmation_modal.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 <div class="modal fade"
      id="confirmation-modal"
      tabindex="-1"
diff --git a/webmentions_ssg/templates/login.html b/webmentions_ssg/templates/login.html
index e7d858c..9b9884e 100644
--- a/webmentions_ssg/templates/login.html
+++ b/webmentions_ssg/templates/login.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% extends "base.html" %}
 {% set title = "Login" %}
 {% from "bootstrap5/form.html" import render_form %}
diff --git a/webmentions_ssg/templates/received.html b/webmentions_ssg/templates/received.html
index 525e811..1c5a216 100644
--- a/webmentions_ssg/templates/received.html
+++ b/webmentions_ssg/templates/received.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% extends "base.html" %}
 {% from "bootstrap5/form.html" import render_form %}
 {% from "bootstrap5/pagination.html" import render_pagination %}
diff --git a/webmentions_ssg/templates/sent.html b/webmentions_ssg/templates/sent.html
index bc9e021..1d311a0 100644
--- a/webmentions_ssg/templates/sent.html
+++ b/webmentions_ssg/templates/sent.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% extends "base.html" %}
 {% from "bootstrap5/form.html" import render_form %}
 {% from "bootstrap5/pagination.html" import render_pagination %}
diff --git a/webmentions_ssg/templates/sent_source.html b/webmentions_ssg/templates/sent_source.html
index 8e5932c..6bb2ac5 100644
--- a/webmentions_ssg/templates/sent_source.html
+++ b/webmentions_ssg/templates/sent_source.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% extends "base.html" %}
 {% block content %}
   <div class="mb-3">
diff --git a/webmentions_ssg/templates/status.html b/webmentions_ssg/templates/status.html
index 451f26f..9140c95 100644
--- a/webmentions_ssg/templates/status.html
+++ b/webmentions_ssg/templates/status.html
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
+
+SPDX-License-Identifier: BSD-3-Clause
+-->
+
 {% extends "base.html" %}
 {% from "bootstrap5/utils.html" import render_icon %}
 {% block content %}