feat: PWA manifest + the Ghost Log (Workstream C)

manifest.webmanifest referencing the icon assets that actually exist
(sizes verified with file, not asserted), standalone display, no service
worker — offline séance is meaningless and SW cache bugs are not worth it.

GET /api/seances/recent: last 12 sessions in exactly three queries
(sessions+entity join, one GROUP BY for counts, one window-function query
for up to 3 echoes per session). Echoes filter on utterance payload kinds
because DB event kinds carry no greeting/manifest — the agent verified
where _speak actually writes rather than trusting the spec's phrasing.

/log page: entity glyphs, relative in-fiction timestamps, counts, echo
lines in transcript style, gated like the séance, 390px-safe.

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

backend/app/routes/seances.py

@@ -0,0 +1,109 @@
+"""Ghost Log recap — a seeker's own recent séances, with who answered and
+what was said. Workstream C of docs/superpowers/specs/
+2026-07-28-usability-wave-design.md (#7)."""
+
+from collections import defaultdict
+
+from fastapi import APIRouter, Depends
+from sqlalchemy import desc, func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.db import get_db
+from app.deps import get_current_user
+from app.models.contact_session import ContactSession
+from app.models.entity import Entity
+from app.models.event import Event
+from app.models.user import User
+
+router = APIRouter(prefix="/api", tags=["seances"])
+
+RECENT_LIMIT = 12
+ECHOES_PER_SESSION = 3
+
+# Spirit speech lands in the DB as kind="utterance" rows whose payload
+# carries the flavor (see app.ws._speak) — these are the ones worth
+# echoing back in a recap.
+ECHO_PAYLOAD_KINDS = ("greeting", "reply", "manifest")
+
+
+@router.get("/seances/recent")
+async def recent_seances(
+    user: User = Depends(get_current_user), db: AsyncSession = Depends(get_db)
+):
+    # One query: the user's last sessions with their entity (may be null).
+    rows = (
+        await db.execute(
+            select(ContactSession, Entity)
+            .outerjoin(Entity, ContactSession.entity_id == Entity.id)
+            .where(ContactSession.user_id == user.id)
+            .order_by(desc(ContactSession.started_at))
+            .limit(RECENT_LIMIT)
+        )
+    ).all()
+
+    session_ids = [session.id for session, _ in rows]
+
+    # One GROUP BY across the fetched sessions for event counts by kind.
+    counts: dict = defaultdict(dict)
+    if session_ids:
+        for session_id, kind, count in await db.execute(
+            select(Event.session_id, Event.kind, func.count(Event.id))
+            .where(Event.session_id.in_(session_ids))
+            .group_by(Event.session_id, Event.kind)
+        ):
+            counts[session_id][kind] = count
+
+    # One bounded query for echoes: top-N spirit utterances per session,
+    # newest first, via a window function — never one query per session.
+    echoes: dict = defaultdict(list)
+    if session_ids:
+        ranked = (
+            select(
+                Event.session_id,
+                Event.text,
+                func.row_number()
+                .over(
+                    partition_by=Event.session_id,
+                    order_by=desc(Event.created_at),
+                )
+                .label("rn"),
+            )
+            .where(
+                Event.session_id.in_(session_ids),
+                Event.kind == "utterance",
+                Event.text.is_not(None),
+                Event.payload["kind"].astext.in_(ECHO_PAYLOAD_KINDS),
+            )
+            .subquery()
+        )
+        for session_id, text, _rn in await db.execute(
+            select(ranked.c.session_id, ranked.c.text, ranked.c.rn).where(
+                ranked.c.rn <= ECHOES_PER_SESSION
+            )
+        ):
+            echoes[session_id].append(text)
+
+    return {
+        "seances": [
+            {
+                "id": str(session.id),
+                "started_at": session.started_at.isoformat(),
+                "ended_at": session.ended_at.isoformat() if session.ended_at else None,
+                "mode": session.mode,
+                "entity": (
+                    {
+                        "id": str(entity.id),
+                        "name": entity.name,
+                        "epithet": entity.epithet,
+                        "rarity": entity.rarity_tier,
+                        "visual": entity.visual_profile,
+                    }
+                    if entity is not None
+                    else None
+                ),
+                "counts": counts.get(session.id, {}),
+                "echoes": echoes.get(session.id, []),
+            }
+            for session, entity in rows
+        ]
+    }