feat(admin): delete a whitelist entry, and stop hiding a broken mail setup

Three operator gaps, all found the same way — a person could not sign up and the
app showed nobody anything.

- DELETE /api/admin/invites/{id} with a delete control on both the pending
  requests and the previously-decided list. Deny keeps the row so the person
  cannot immediately re-ask; delete forgets the address. Refused with 409 while
  a User row exists for it, because is_allowed reads that row and removing it
  would revoke a live user's access with no other sign — the list ships
  has_account so the UI withholds the button instead of offering one that fails.
- Email is fail-soft by design, which had come to mean invisible. _send() now
  records an email_undelivered notification for every admin when a message is
  skipped or rejected, naming the message that was lost, throttled to one an
  hour. /api/me carries email_configured, driving a standing warning on
  Configuration → Email / SMTP and above the access-request list.
- The sign-in card's Create account / Forgot password / Didn't get the email
  views are history entries (useHistorySubview), so Back returns to the previous
  view instead of only moving the address bar.

Also: the per-test rate-limiter reset sweeps every loaded app.* module rather
than a hand-kept list of three — this change added a limiter outside it.

backend/tests/conftest.py

@@ -196,13 +196,17 @@ def _reset_rate_limiters():
     """Every RateLimiter is a module-level singleton keyed by client IP, and TestClient always
     presents the same host — so without this the whole suite's login/register attempts pool into one
     300s window and, past the cap, some unrelated test starts failing with a 429 depending on order.
-    Cleared before each test; a test that wants to exercise throttling can still exhaust one itself."""
-    import app.routes.auth as _auth
-    import app.routes.messages as _messages
-    import app.routes.public as _public
+    Cleared before each test; a test that wants to exercise throttling can still exhaust one itself.
+
+    Sweeps every loaded `app.*` module rather than a hand-kept list, so a limiter added in a new
+    module is covered the day it lands instead of silently pooling until something fails."""
+    import sys
+
     from app.ratelimit import RateLimiter
 
-    for mod in (_auth, _messages, _public):
+    for name, mod in list(sys.modules.items()):
+        if name != "app" and not name.startswith("app."):
+            continue
         for obj in vars(mod).values():
             if isinstance(obj, RateLimiter):
                 obj.reset()

backend/tests/test_admin_invites.py

@@ -0,0 +1,106 @@
+"""Deleting a whitelist / access-request entry (admin).
+
+Deny keeps the row so a refused person cannot immediately re-ask; delete forgets the address
+outright, for an approval added by mistake or one that is no longer wanted. The one hard rule is
+that an entry backed by an account is NOT deletable here: `is_allowed` reads this row, so removing
+it would silently revoke a live user's access.
+"""
+
+from sqlalchemy import select
+
+from app.models import Invite, User
+
+
+def _invites(client):
+    r = client.get("/api/admin/invites")
+    assert r.status_code == 200
+    return {i["email"]: i for i in r.json()}
+
+
+def test_admin_deletes_a_whitelist_entry_that_never_became_an_account(db, make_user, as_user):
+    admin = make_user(email="admin@example.com", role="admin")
+    db.add(Invite(email="mistake@example.com", status="approved", decided_by=admin.email))
+    db.commit()
+    client = as_user(admin)
+    listed = _invites(client)["mistake@example.com"]
+    assert listed["has_account"] is False  # drives the delete affordance in the UI
+
+    r = client.delete(f"/api/admin/invites/{listed['id']}")
+
+    assert r.status_code == 200 and r.json() == {"deleted": listed["id"]}
+    db.expire_all()
+    assert (
+        db.execute(select(Invite).where(Invite.email == "mistake@example.com")).scalar_one_or_none()
+        is None
+    )
+
+
+def test_deleting_an_entry_that_has_an_account_is_refused(db, make_user, as_user):
+    # The guard that matters: this row is what is_allowed() reads, so deleting it would revoke the
+    # user's access without touching the account or saying so.
+    admin = make_user(email="admin@example.com", role="admin")
+    member = make_user(email="member@example.com")
+    db.add(Invite(email=member.email, status="approved", decided_by=admin.email))
+    db.commit()
+    client = as_user(admin)
+    listed = _invites(client)[member.email]
+    assert listed["has_account"] is True
+
+    r = client.delete(f"/api/admin/invites/{listed['id']}")
+
+    assert r.status_code == 409
+    db.expire_all()
+    assert (
+        db.execute(select(Invite).where(Invite.email == member.email)).scalar_one_or_none()
+        is not None
+    )
+
+
+def test_deleting_a_pending_request_forgets_it(db, make_user, as_user):
+    # A pending row is deletable too — "not now, and don't keep the record" is a different decision
+    # from Deny, which keeps the row precisely so the person cannot immediately re-ask.
+    admin = make_user(email="admin@example.com", role="admin")
+    db.add(Invite(email="asker@example.com", status="pending"))
+    db.commit()
+    client = as_user(admin)
+
+    r = client.delete(f"/api/admin/invites/{_invites(client)['asker@example.com']['id']}")
+
+    assert r.status_code == 200
+    assert "asker@example.com" not in _invites(client)
+
+
+def test_deleting_a_missing_invite_is_404(db, make_user, as_user):
+    admin = make_user(email="admin@example.com", role="admin")
+    assert as_user(admin).delete("/api/admin/invites/9999").status_code == 404
+
+
+def test_a_regular_user_cannot_delete_an_invite(db, make_user, as_user):
+    make_user(email="admin@example.com", role="admin")
+    plain = make_user(email="plain@example.com")
+    db.add(Invite(email="mistake@example.com", status="approved"))
+    db.commit()
+    inv_id = db.execute(select(Invite.id).where(Invite.email == "mistake@example.com")).scalar_one()
+
+    assert as_user(plain).delete(f"/api/admin/invites/{inv_id}").status_code == 403
+
+    db.expire_all()
+    assert db.get(Invite, inv_id) is not None
+
+
+def test_deleting_the_user_also_clears_the_way_to_re_invite(db, make_user, as_user):
+    # The refusal above tells the admin to delete the account instead; purge_user takes the invite
+    # with it, so the address really is forgotten and a fresh request starts over as pending.
+    admin = make_user(email="admin@example.com", role="admin")
+    member = make_user(email="member@example.com")
+    db.add(Invite(email=member.email, status="approved", decided_by=admin.email))
+    db.commit()
+    client = as_user(admin)
+
+    assert client.delete(f"/api/admin/users/{member.id}").status_code == 200
+
+    db.expire_all()
+    assert db.execute(select(User).where(User.email == member.email)).scalar_one_or_none() is None
+    assert (
+        db.execute(select(Invite).where(Invite.email == member.email)).scalar_one_or_none() is None
+    )

backend/tests/test_email_alerts.py

@@ -0,0 +1,115 @@
+"""An undelivered email leaves a trace in the admins' inbox.
+
+Sending is deliberately fail-soft — a missing SMTP setting or a rejecting relay logs and returns
+False so nothing user-facing breaks. The cost of that used to be total silence: an instance whose
+SMTP was never filled in swallowed verification links, password resets and access-request notices,
+and the operator's first clue was somebody saying nothing arrived.
+"""
+
+import smtplib
+
+import pytest
+from sqlalchemy import select
+
+from app import email as email_mod
+from app.models import Notification
+
+
+@pytest.fixture(autouse=True)
+def _no_smtp_config(monkeypatch):
+    """Every test here drives the real `_send`, so make sure it never reaches a socket."""
+    monkeypatch.setattr(
+        email_mod,
+        "_smtp",
+        lambda: {"host": "", "port": 587, "user": "", "password": "", "from": ""},
+    )
+
+
+def _notifications(db, user_id: int) -> list[Notification]:
+    return list(
+        db.execute(
+            select(Notification)
+            .where(Notification.user_id == user_id, Notification.type == "email_undelivered")
+            .order_by(Notification.id)
+        )
+        .scalars()
+        .all()
+    )
+
+
+def test_a_skipped_email_notifies_every_admin(db, make_user):
+    admin_a = make_user(email="admin-a@example.com", role="admin")
+    admin_b = make_user(email="admin-b@example.com", role="admin")
+    plain = make_user(email="plain@example.com")
+
+    assert email_mod.send_test("someone@example.com") is False  # fail-soft, as before
+
+    db.expire_all()
+    for admin in (admin_a, admin_b):
+        (n,) = _notifications(db, admin.id)
+        assert n.data["reason"] == "not_configured"
+        assert n.data["subject"] == "Siftlode SMTP test"
+        assert n.data["recipients"] == ["someone@example.com"]
+    assert _notifications(db, plain.id) == []  # not an operator's problem to see
+
+
+def test_the_notice_is_throttled_so_a_dead_relay_cannot_flood_the_inbox(db, make_user):
+    admin = make_user(email="admin@example.com", role="admin")
+
+    for _ in range(5):
+        email_mod.send_test("someone@example.com")
+
+    db.expire_all()
+    assert len(_notifications(db, admin.id)) == 1
+
+
+def test_a_send_failure_is_reported_separately_from_a_missing_config(db, make_user, monkeypatch):
+    # A configured-but-rejecting relay is a different operator problem from an empty config, and the
+    # inbox copy differs — so the reason has to survive to the notification.
+    admin = make_user(email="admin@example.com", role="admin")
+    monkeypatch.setattr(
+        email_mod,
+        "_smtp",
+        lambda: {
+            "host": "smtp.example.com",
+            "port": 587,
+            "user": "u",
+            "password": "p",
+            "from": "Siftlode <u@example.com>",
+        },
+    )
+
+    def _boom(*a, **kw):
+        raise smtplib.SMTPException("nope")
+
+    monkeypatch.setattr(email_mod.smtplib, "SMTP", _boom)
+
+    assert email_mod.send_test("someone@example.com") is False
+
+    db.expire_all()
+    (n,) = _notifications(db, admin.id)
+    assert n.data["reason"] == "send_failed"
+
+
+def test_no_admins_means_no_notification_and_no_error(db, make_user):
+    # A fresh instance can have no admin yet (the wizard has not run). The alert must stay silent
+    # rather than blowing up inside the fail-soft path it is supposed to make visible.
+    plain = make_user(email="plain@example.com")
+
+    assert email_mod.send_test("someone@example.com") is False
+
+    db.expire_all()
+    assert _notifications(db, plain.id) == []
+
+
+def test_a_broken_alert_never_breaks_the_send(db, make_user, monkeypatch):
+    # The alert is the fallback path; if IT fails, the caller must still get the ordinary fail-soft
+    # False rather than an exception surfacing from a background task.
+    make_user(email="admin@example.com", role="admin")
+
+    def _boom(*a, **kw):
+        raise RuntimeError("notification store is down")
+
+    monkeypatch.setattr(email_mod, "create_notification", _boom)
+
+    assert email_mod.send_test("someone@example.com") is False