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/base.html

@@ -16,17 +16,21 @@
     <header>
       <h1><a href="/">{{ title or 'Admin' }}</a></h1>
       <nav>
-        {% if username %}<span>Hi, {{ username }}</span> | {% endif %}
-        <a href="{{ url_for('index') }}">Home</a> |
-        <a href="{{ url_for('user_settings') }}">Preferences</a>
-        {% if current_user and current_user.is_admin %} |
-        <a href="{{ url_for('scrape_page') }}">Scrape Jobs</a> |
-        <a href="{{ url_for('admin_taxonomy') }}">Taxonomy</a> |
-        <a href="{{ url_for('admin_stats') }}">Statistics</a> |
-        <a href="{{ url_for('admin_users') }}">Users</a> {% endif %} {% if
-        session.get('username') %} |
-        <a href="{{ url_for('logout') }}">Logout</a> {% else %} |
-        <a href="{{ url_for('login') }}">Login</a>{% endif %}
+        <div id="navigation">
+          {% if username %}<span>Hi, {{ username }}</span> | {% endif %}
+          <a href="{{ url_for('index') }}">Home</a> |
+          <a href="{{ url_for('user_settings') }}">Preferences</a>
+          {% if current_user and current_user.is_admin %} |
+          <a href="{{ url_for('scrape_page') }}">Scrape Jobs</a> |
+          <a href="{{ url_for('admin_taxonomy') }}">Taxonomy</a> |
+          <a href="{{ url_for('admin_stats') }}">Statistics</a> |
+          <a href="{{ url_for('admin_emails') }}">Email Alerts</a> |
+          <a href="{{ url_for('admin_email_templates') }}">Email Templates</a> |
+          <a href="{{ url_for('admin_users') }}">Users</a> {% endif %} {% if
+          session.get('username') %} |
+          <a href="{{ url_for('logout') }}">Logout</a> {% else %} |
+          <a href="{{ url_for('login') }}">Login</a>{% endif %}
+        </div>
       </nav>
       {% with messages = get_flashed_messages() %} {% if messages %}
       <ul>