feat(sender): add outgoing Webmention pipeline

Scan generated h-entry documents for Webmention targets and track source
revisions and delivery state in the database.

Discover target endpoints, send Webmentions asynchronously, and reconcile
updated, removed, restored, and deleted sources across scans.

Add authenticated views for inspecting sent Webmentions and make the scanner
schedule configurable.

1 files changed, 61 insertions, 0 deletions

diff --git a/webmentions_ssg/templates/sent.html b/webmentions_ssg/templates/sent.html
new file mode 100644
index 0000000..69a91d8
--- /dev/null
+++ b/webmentions_ssg/templates/sent.html
@@ -0,0 +1,61 @@
+{% extends "base.html" %}
+{% from "bootstrap5/pagination.html" import render_pagination %}
+{% block content %}
+  <div class="d-flex justify-content-between align-items-center mb-3">
+    <h1 class="mb-0">Sources</h1>
+    <span class="text-body-secondary">{{ sources.total }} sources</span>
+  </div>
+  {% if sources.items %}
+    <div class="table-responsive">
+      <table class="table table-bordered table-striped table-hover align-middle">
+        <thead>
+          <tr>
+            <th scope="col">Path</th>
+            <th scope="col">URL</th>
+            <th scope="col">Webmentions</th>
+            <th scope="col">Revision</th>
+            <th scope="col">Created</th>
+            <th scope="col">Last seen</th>
+            <th scope="col">Status</th>
+          </tr>
+        </thead>
+        <tbody>
+          {% for source in sources %}
+            <tr>
+              <td class="text-nowrap">
+                <a href="{{ url_for('root.sent_source', identifier=source.uuid) }}">{{ source.path }}</a>
+              </td>
+              <td class="text-break">
+                <a href="{{ source.url }}">{{ source.url }}</a>
+              </td>
+              <td>{{ source.sent_webmentions | length }}</td>
+              <td>{{ source.revision }}</td>
+              <td class="text-nowrap">
+                <time datetime="{{ source.created_at.isoformat() }}">
+                  {{ source.created_at.strftime("%Y-%m-%d %H:%M:%S") }}
+                </time>
+              </td>
+              <td class="text-nowrap">
+                <time datetime="{{ source.last_seen_at.isoformat() }}">
+                  {{ source.last_seen_at.strftime("%Y-%m-%d %H:%M:%S") }}
+                </time>
+              </td>
+              <td>
+                {% if source.deleted_at is none %}
+                  <span class="badge text-bg-success">Active</span>
+                {% else %}
+                  <span class="badge text-bg-danger">Deleted</span>
+                {% endif %}
+              </td>
+            </tr>
+          {% endfor %}
+        </tbody>
+      </table>
+    </div>
+    {% if sources.pages > 1 %}
+      <div class="mt-3">{{ render_pagination(sources) }}</div>
+    {% endif %}
+  {% else %}
+    <p class="text-body-secondary">No Webmention sources have been discovered yet.</p>
+  {% endif %}
+{% endblock %}