feat: Implement email sending utilities and templates for job notifications

- Added email_service.py for sending emails with SMTP configuration.
- Introduced email_templates.py to render job alert email subjects and bodies.
- Enhanced scraper.py to extract contact information from job listings.
- Updated settings.js to handle negative keyword input validation.
- Created email.html and email_templates.html for managing email subscriptions and templates in the admin interface.
- Modified base.html to include links for email alerts and templates.
- Expanded user settings.html to allow management of negative keywords.
- Updated utils.py to include functions for retrieving negative keywords and email settings.
- Enhanced job filtering logic to exclude jobs containing negative keywords.

web/templates/admin/email_templates.html

@@ -0,0 +1,102 @@
+{% extends 'base.html' %}
+{% block content %}
+<h2>Email Templates</h2>
+<section>
+  <h3>Available Templates</h3>
+  {% if not templates %}
+  <p>No templates found. Create one below to get started.</p>
+  {% else %}
+  <table>
+    <thead>
+      <tr>
+        <th>Name</th>
+        <th>Slug</th>
+        <th>Status</th>
+        <th>Updated</th>
+        <th>Actions</th>
+      </tr>
+    </thead>
+    <tbody>
+      {% for template in templates %}
+      <tr>
+        <td>{{ template.name }}</td>
+        <td>{{ template.slug }}</td>
+        <td>{{ 'Active' if template.is_active else 'Inactive' }}</td>
+        <td>{{ template.updated_at or template.created_at or '' }}</td>
+        <td style="display: flex; gap: 0.5rem;">
+          <a class="button" href="{{ url_for('admin_email_templates', template_id=template.template_id) }}">Edit</a>
+          <a class="button" href="{{ url_for('admin_email_templates', preview_id=template.template_id) }}">Preview</a>
+          <form method="post" onsubmit="return confirm('Delete template {{ template.name }}?');">
+            <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" />
+            <input type="hidden" name="action" value="delete" />
+            <input type="hidden" name="template_id" value="{{ template.template_id }}" />
+            <button type="submit">Delete</button>
+          </form>
+        </td>
+      </tr>
+      {% endfor %}
+    </tbody>
+  </table>
+  {% endif %}
+</section>
+<section>
+  <h3>{{ 'Edit Template' if editing else 'Create Template' }}</h3>
+  <form method="post">
+    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" />
+    <input type="hidden" name="action" value="{{ 'update' if editing else 'create' }}" />
+    {% if editing %}
+    <input type="hidden" name="template_id" value="{{ editing.template_id }}" />
+    {% endif %}
+    <div>
+      <label for="name">Name</label>
+      <input type="text" id="name" name="name" value="{{ editing.name if editing else '' }}" required />
+    </div>
+    <div>
+      <label for="slug">Slug</label>
+      <input type="text" id="slug" name="slug" placeholder="job-alert" value="{{ editing.slug if editing else '' }}" />
+      <small>Leave blank to reuse the name. Slug must be URL friendly (letters, numbers, dashes).</small>
+    </div>
+    <div>
+      <label for="subject">Subject Template</label>
+      <input type="text" id="subject" name="subject" value="{{ editing.subject if editing else '' }}" required />
+    </div>
+    <div>
+      <label for="body">Body Template</label>
+      <textarea id="body" name="body" rows="12" required>{{ editing.body if editing else '' }}</textarea>
+    </div>
+    <div>
+      <label>
+        <input type="checkbox" name="is_active" {% if editing is none or editing.is_active %}checked{% endif %} />
+        Active
+      </label>
+    </div>
+    <button type="submit">{{ 'Update Template' if editing else 'Create Template' }}</button>
+    {% if editing %}
+    <a class="button" href="{{ url_for('admin_email_templates') }}">Cancel</a>
+    {% endif %}
+  </form>
+  <aside>
+    <h4>Available placeholders</h4>
+    <ul>
+      <li><code>{count}</code> – number of jobs in the alert</li>
+      <li><code>{count_label}</code> – "No new jobs" or "X new jobs"</li>
+      <li><code>{scope}</code> – formatted region/keyword context</li>
+      <li><code>{region}</code>, <code>{keyword}</code></li>
+      <li><code>{timestamp}</code> – formatted timestamp</li>
+      <li><code>{jobs_section}</code> – newline-prefixed block of job entries</li>
+      <li><code>{jobs_message}</code> – jobs block without leading newline</li>
+    </ul>
+  </aside>
+</section>
+{% if preview %}
+<section>
+  <h3>Preview: {{ preview_template.name if preview_template else 'Job Alert' }}</h3>
+  <article>
+    <h4>Subject</h4>
+    <pre>{{ preview.subject }}</pre>
+    <h4>Body</h4>
+    <pre>{{ preview.body }}</pre>
+  </article>
+</section>
+{% endif %}
+{% endblock %}