feat: presence beyond the tab — PWA manifest and the Ghost Log recap

Usability wave Workstream C (#5, #7):
- manifest.webmanifest with existing 192/512/180 icons, linked in
  index.html with theme-color aligned to #07070d; no service worker.
- GET /api/seances/recent: last 12 of the seeker's own séances with
  entity, per-kind event counts (one GROUP BY) and up to 3 spirit
  echoes (one windowed query) — no per-session N+1.
- /log Ghost Log page: cards with GhostGlyph, relative in-fiction
  timestamps, counts and echo lines; LOG link in the séance topbar;
  en/es i18n parity.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/tests/test_seances.py

@@ -0,0 +1,151 @@
+"""Tests for GET /api/seances/recent — the Ghost Log recap
+(usability wave, Workstream C, #7)."""
+
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+from app.models.contact_session import ContactSession
+from app.models.entity import Entity
+from app.models.event import Event
+
+
+async def _register(client, username):
+    resp = await client.post(
+        "/auth/register", json={"username": username, "password": "spookyspooky"}
+    )
+    assert resp.status_code == 201
+    return resp.json()["id"]
+
+
+async def _login(client, username):
+    resp = await client.post(
+        "/auth/login", json={"username": username, "password": "spookyspooky"}
+    )
+    assert resp.status_code == 200
+
+
+def _entity(name, signature):
+    return Entity(
+        name=name,
+        epithet="the Test Wraith",
+        rarity_tier="rare",
+        signature=signature,
+        visual_profile={"hue": 200, "form": "wisp"},
+    )
+
+
+@pytest.mark.asyncio
+async def test_unauthenticated_rejected(client):
+    resp = await client.get("/api/seances/recent")
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_only_own_sessions_newest_first_with_counts_and_echoes(client, db_session):
+    my_id = await _register(client, "seeker1")
+    other_id = await _register(client, "seeker2")
+    await _login(client, "seeker1")
+
+    entity = _entity("Testnamed", "sig-aaaa")
+    db_session.add(entity)
+    await db_session.flush()
+
+    now = datetime.now(timezone.utc)
+    older = ContactSession(
+        user_id=my_id, entity_id=entity.id, mode="evp", started_at=now - timedelta(hours=2)
+    )
+    newer = ContactSession(
+        user_id=my_id, entity_id=entity.id, mode="wire", started_at=now - timedelta(hours=1)
+    )
+    theirs = ContactSession(user_id=other_id, mode="ouija", started_at=now)
+    db_session.add_all([older, newer, theirs])
+    await db_session.flush()
+
+    # Events on the newer session: 2 questions, 3 anomalies, 4 spirit
+    # utterances (only the newest 3 should come back as echoes).
+    events = [
+        Event(session_id=newer.id, kind="question", text="who's there?"),
+        Event(session_id=newer.id, kind="question", text="still there?"),
+        Event(session_id=newer.id, kind="anomaly", payload={"score": 1}),
+        Event(session_id=newer.id, kind="anomaly", payload={"score": 2}),
+        Event(session_id=newer.id, kind="anomaly", payload={"score": 3}),
+    ]
+    for i in range(4):
+        events.append(
+            Event(
+                session_id=newer.id,
+                kind="utterance",
+                text=f"echo {i}",
+                payload={"kind": "reply"},
+                created_at=now - timedelta(minutes=30 - i),
+            )
+        )
+    # An utterance on the OTHER user's session must never leak.
+    events.append(
+        Event(
+            session_id=theirs.id,
+            kind="utterance",
+            text="not yours",
+            payload={"kind": "greeting"},
+        )
+    )
+    db_session.add_all(events)
+    await db_session.commit()
+
+    resp = await client.get("/api/seances/recent")
+    assert resp.status_code == 200
+    seances = resp.json()["seances"]
+
+    # Only my sessions, newest first.
+    assert [s["id"] for s in seances] == [str(newer.id), str(older.id)]
+
+    first = seances[0]
+    assert first["mode"] == "wire"
+    assert first["counts"] == {"question": 2, "anomaly": 3, "utterance": 4}
+    assert first["echoes"] == ["echo 3", "echo 2", "echo 1"]
+    assert first["entity"] == {
+        "id": str(entity.id),
+        "name": "Testnamed",
+        "epithet": "the Test Wraith",
+        "rarity": "rare",
+        "visual": {"hue": 200, "form": "wisp"},
+    }
+
+    # No cross-user text anywhere in the response.
+    assert "not yours" not in resp.text
+
+
+@pytest.mark.asyncio
+async def test_session_without_entity_does_not_crash(client, db_session):
+    my_id = await _register(client, "seeker3")
+    await _login(client, "seeker3")
+
+    session = ContactSession(user_id=my_id, mode="ouija")
+    db_session.add(session)
+    await db_session.commit()
+
+    resp = await client.get("/api/seances/recent")
+    assert resp.status_code == 200
+    seances = resp.json()["seances"]
+    assert len(seances) == 1
+    assert seances[0]["entity"] is None
+    assert seances[0]["counts"] == {}
+    assert seances[0]["echoes"] == []
+
+
+@pytest.mark.asyncio
+async def test_limited_to_twelve(client, db_session):
+    my_id = await _register(client, "seeker4")
+    await _login(client, "seeker4")
+
+    now = datetime.now(timezone.utc)
+    db_session.add_all(
+        ContactSession(user_id=my_id, mode="wire", started_at=now - timedelta(minutes=i))
+        for i in range(15)
+    )
+    await db_session.commit()
+
+    resp = await client.get("/api/seances/recent")
+    assert resp.status_code == 200
+    assert len(resp.json()["seances"]) == 12