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.

tests/test_email_service.py

@@ -0,0 +1,106 @@
+import pytest
+
+from web.email_service import (
+    EmailConfigurationError,
+    send_email,
+)
+
+
+def test_send_email_disabled(monkeypatch):
+    called = {}
+
+    def _fake_smtp(*args, **kwargs):  # pragma: no cover - should not be called
+        called["used"] = True
+        raise AssertionError(
+            "SMTP should not be invoked when email is disabled")
+
+    monkeypatch.setattr("web.email_service.smtplib.SMTP", _fake_smtp)
+    monkeypatch.setattr("web.email_service.smtplib.SMTP_SSL", _fake_smtp)
+
+    result = send_email(
+        subject="Hi",
+        body="Test",
+        to="user@example.com",
+        settings={"enabled": False},
+    )
+    assert result is False
+    assert called == {}
+
+
+def test_send_email_sends_message(monkeypatch):
+    events = {"starttls": False, "login": None, "sent": None}
+
+    class FakeSMTP:
+        def __init__(self, *, host, port, timeout):
+            self.host = host
+            self.port = port
+            self.timeout = timeout
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc, tb):
+            return False
+
+        def ehlo(self):
+            events.setdefault("ehlo", 0)
+            events["ehlo"] += 1
+
+        def starttls(self):
+            events["starttls"] = True
+
+        def login(self, username, password):
+            events["login"] = (username, password)
+
+        def send_message(self, message, *, from_addr, to_addrs):
+            events["sent"] = {
+                "from": from_addr,
+                "to": tuple(to_addrs),
+                "subject": message["Subject"],
+            }
+
+    monkeypatch.setattr("web.email_service.smtplib.SMTP", FakeSMTP)
+    monkeypatch.setattr("web.email_service.smtplib.SMTP_SSL", FakeSMTP)
+
+    settings = {
+        "enabled": True,
+        "from_address": "jobs@example.com",
+        "smtp": {
+            "host": "smtp.example.com",
+            "port": 2525,
+            "timeout": 15,
+            "username": "jobs",
+            "password": "secret",
+            "use_tls": True,
+            "use_ssl": False,
+        },
+    }
+
+    result = send_email(
+        subject="New Jobs",
+        body="You have new jobs waiting.",
+        to=["a@example.com", "b@example.com"],
+        cc="c@example.com",
+        bcc=["d@example.com"],
+        settings=settings,
+    )
+
+    assert result is True
+    assert events["starttls"] is True
+    assert events["login"] == ("jobs", "secret")
+    assert events["sent"] == {
+        "from": "jobs@example.com",
+        "to": ("a@example.com", "b@example.com", "c@example.com", "d@example.com"),
+        "subject": "New Jobs",
+    }
+
+
+def test_send_email_requires_host():
+    settings = {
+        "enabled": True,
+        "from_address": "jobs@example.com",
+        "smtp": {"host": "", "port": 587},
+    }
+    with pytest.raises(EmailConfigurationError):
+        send_email(subject="Hi", body="Test",
+                   to="user@example.com", settings=settings)