feat!: remove direct messaging (chat)

E2EE direct messages, the chat dock, the Messages module, the message
WebSocket and its realtime registry, and the messages / message_keys
tables (migration 0097; the downgrade restores the empty schema). Prod
held two welcome notes, no message between people and one key — never
used (owner decision, E34). WebSocket now has no owner module: the lint
bans it everywhere. Privacy policy updated: it no longer promises E2EE
for a feature that is gone.

backend/tests/fixtures/log_redaction_cases.json

@@ -31,7 +31,7 @@
       }
     },
     {
-      "name": "E2EE material and cookies",
+      "name": "ciphertext, passphrases and cookies",
       "key": "",
       "value": {
         "ciphertext": "AAAA",

backend/tests/test_collation.py

@@ -221,30 +221,13 @@ def _others(db, n_offset: int = 0) -> list[User]:
     return users
 
 
-def test_the_share_and_message_recipients_are_in_the_readers_alphabet(
-    db, monkeypatch, override_dep
-):
-    from app.models import MessageKey
-
+def test_the_share_recipients_are_in_the_readers_alphabet(db, monkeypatch, override_dep):
     user = _user(db, "hu")
-    others = _others(db)
-    db.add_all(
-        MessageKey(
-            user_id=u.id,
-            public_key="k",
-            wrapped_private_key="w",
-            salt="s",
-            wrap_iv="i",
-            key_check="c",
-        )
-        for u in others
-    )
+    _others(db)
     db.commit()
     client = _client(db, user, monkeypatch, override_dep)
     emails = [r["email"] for r in client.get("/api/downloads/recipients").json()]
     assert emails == [f"{w.lower()}@example.com" for w in HU]
-    names = [r["name"] for r in client.get("/api/messages/users").json()]
-    assert names == HU
 
 
 def test_the_blocked_channels_are_in_the_readers_alphabet(db, monkeypatch, override_dep):

backend/tests/test_logs.py

@@ -219,11 +219,11 @@ def _client() -> TestClient:
             raise HTTPException(status_code=400, detail={"code": "bad_cursor"})
         return {"ok": True}
 
-    @app.get("/api/messages/unread_count")
+    @app.get("/api/me/notifications/unread_count")
     def _unread():
         return {"count": 0}
 
-    @app.post("/api/messages/unread_count")
+    @app.post("/api/me/notifications/unread_count")
     def _unread_write():
         return {"ok": True}
 
@@ -337,11 +337,11 @@ def test_a_polled_read_is_debug_a_write_to_the_same_route_is_not(sink):
     http = logging.getLogger("siftlode.http")
     http.setLevel(logs.TRACE)
     client = _client()
-    r = client.get("/api/messages/unread_count")
+    r = client.get("/api/me/notifications/unread_count")
     assert sink.objects()[-1]["level"] == "DEBUG"
     # ...and says so, for the browser's copy of the line (frontend lib/http.ts).
     assert r.headers["X-Log-Quiet"] == "1"
-    r = client.post("/api/messages/unread_count")
+    r = client.post("/api/me/notifications/unread_count")
     assert sink.objects()[-1]["level"] == "INFO"
     assert "X-Log-Quiet" not in r.headers
     assert client.get("/api/videos/abc").status_code == 200

backend/tests/test_messages_welcome.py

@@ -1,53 +0,0 @@
-"""E31 S1: the welcome message is rendered once, when the account is created, in the language of that day.
-An account that switched language afterwards kept reading it in the old one (the owner's: English under a
-Hungarian UI). It is served in the reader's language now; any other system message stays as stored.
-Needs the DB."""
-
-from fastapi.testclient import TestClient
-
-import app.state as state
-from app.auth import current_user
-from app.db import get_db
-from app.main import app
-from app.models import Message, User
-from app.routes.messages import WELCOME
-
-
-def _client(db, user, monkeypatch, override_dep) -> TestClient:
-    monkeypatch.setattr(state, "_configured_cache", True)
-    override_dep(get_db, db.info["request"])
-    override_dep(current_user, lambda: user)
-    return TestClient(app)
-
-
-def _user_with_english_welcome(db) -> User:
-    """An account whose welcome was written in English, then switched to Hungarian."""
-    user = User(email="welcome-hu@example.com", preferences={"language": "hu"})
-    db.add(user)
-    db.flush()
-    db.add(Message(kind="system", sender_id=None, recipient_id=user.id, body=WELCOME["en"]))
-    db.commit()
-    return user
-
-
-def test_the_welcome_is_read_in_the_readers_language(db, monkeypatch, override_dep):
-    user = _user_with_english_welcome(db)
-    client = _client(db, user, monkeypatch, override_dep)
-
-    thread = client.get("/api/messages/conversations/0").json()["items"]
-    assert [m["body"] for m in thread] == [WELCOME["hu"]]
-
-    convs = client.get("/api/messages/conversations").json()["items"]
-    assert [c["last_message"]["body"] for c in convs if c["partner"]["id"] == 0] == [WELCOME["hu"]]
-
-
-def test_another_system_message_is_served_as_stored(db, monkeypatch, override_dep):
-    user = _user_with_english_welcome(db)
-    db.add(
-        Message(kind="system", sender_id=None, recipient_id=user.id, body="Maintenance tonight.")
-    )
-    db.commit()
-    client = _client(db, user, monkeypatch, override_dep)
-
-    bodies = [m["body"] for m in client.get("/api/messages/conversations/0").json()["items"]]
-    assert bodies == [WELCOME["hu"], "Maintenance tonight."]

backend/tests/test_route_conventions.py

@@ -23,11 +23,9 @@ COMMITTING_HELPERS = {
     "search.py:_ingest_candidates": "stages around YouTube calls: the stubs must survive an enrich "
     "that fails",
     "search.py:_classify_shorts": "the last stage of that ingest, after its probes",
-    "auth.py:upsert_pending_invite": "commits only when it writes — the contract its three "
+    "auth.py:upsert_pending_invite": "commits only when it writes — the contract its two "
     "callers rely on (`_register_account` persists its own flushed user because a no-op here "
     "commits nothing)",
-    "messages.py:ensure_welcome": "the websocket push after it must announce a row the client "
-    "can already fetch",
     "debug_sessions.py:_end_send": "gives back the claim a send took, in a `finally`: it runs when "
     "the handler is already unwinding and has no commit left to reach",
 }