feat: session modes (Talk/Cash) + live session HUD

Lyra now switches register based on what she's doing at the table instead of
being a wishy-washy companion mid-session.

Modes (lyra/modes.py):
- Talk (default companion) + Cash (live cash copilot); a mode = prompt card +
  tool allow-list. Tool gating via tools.specs(allow=).
- Two-register Cash voice: act-first one-line logging when fed facts; full warm
  companion voice for strategy / tilt / mental game.
- mode persisted per chat session (new sessions.mode column); auto-switch into
  Cash when start_session fires; UI forces cloud backend in Cash (tools only
  fire there).

Stack tracking + HUD:
- log_stack tool + poker_stack_log table; live net while sitting (stack - buy-in).
- poker.hud() bundle; /session HUD page (stack sparkline, hands, villains, notes,
  stats) polling /session/data every 5s; Talk/Cash switcher + Session nav.

Endpoints: /session, /session/data, GET/POST /sessions/{id}/mode, /modes.
tests/test_modes.py (gating, mode roundtrip, stack/HUD); 36 tests green. v0.3.0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyra/poker.py

@@ -98,6 +98,16 @@ CREATE TABLE IF NOT EXISTS player_observations (
     created_at TEXT NOT NULL
 );
 CREATE INDEX IF NOT EXISTS idx_pobs_player ON player_observations(player_id);
+
+-- Stack-size log: one row per stack update Brian gives during a session. Lets the
+-- HUD show current stack, live net while sitting, and a stack-over-time sparkline.
+CREATE TABLE IF NOT EXISTS poker_stack_log (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    session_id INTEGER NOT NULL,
+    amount REAL NOT NULL,
+    created_at TEXT NOT NULL
+);
+CREATE INDEX IF NOT EXISTS idx_stacklog_session ON poker_stack_log(session_id);
 """
 
 # Below this many observed hands, don't surface % stats (too small a sample).
@@ -212,6 +222,59 @@ def add_buyin(amount: float, session_id: int | None = None) -> float:
     ).fetchone()["buy_in_total"])
 
 
+# --- stack tracking ---
+
+def log_stack(amount: float, session_id: int | None = None) -> dict:
+    """Record Brian's current chip stack. Returns {current, buy_in, net} where net
+    is his live net while sitting (current stack − total bought in)."""
+    sid = _resolve(session_id)
+    if sid is None:
+        raise ValueError("no live session")
+    conn = _c()
+    with conn:
+        conn.execute(
+            "INSERT INTO poker_stack_log (session_id, amount, created_at) VALUES (?, ?, ?)",
+            (sid, float(amount), _now()),
+        )
+    return stack_state(sid)
+
+
+def current_stack(session_id: int | None = None) -> float | None:
+    """Most recently logged stack for a session, or None if none logged."""
+    sid = _resolve(session_id)
+    if sid is None:
+        return None
+    r = _c().execute(
+        "SELECT amount FROM poker_stack_log WHERE session_id = ? ORDER BY id DESC LIMIT 1",
+        (sid,),
+    ).fetchone()
+    return float(r["amount"]) if r else None
+
+
+def stack_log(session_id: int | None = None) -> list[dict]:
+    """Full stack history for a session (oldest first) — the sparkline series."""
+    sid = _resolve(session_id)
+    if sid is None:
+        return []
+    return [dict(r) for r in _c().execute(
+        "SELECT amount, created_at FROM poker_stack_log WHERE session_id = ? ORDER BY id",
+        (sid,),
+    ).fetchall()]
+
+
+def stack_state(session_id: int | None = None) -> dict:
+    """Current stack + buy-in + live net for a session (net None until a stack is logged)."""
+    sid = _resolve(session_id)
+    s = get_session(sid) if sid is not None else None
+    buy_in = float(s["buy_in_total"]) if s else 0.0
+    cur = current_stack(sid)
+    return {
+        "current": cur,
+        "buy_in": buy_in,
+        "net": (round(cur - buy_in, 2) if cur is not None else None),
+    }
+
+
 def end_session(cash_out: float, mood: str | None = None,
                 session_id: int | None = None) -> dict:
     """Close a session: record cashout, compute net + hours. Returns the row."""
@@ -752,3 +815,76 @@ def running_stats(stakes: str | None = None, venue: str | None = None,
         "per_hour": round(net / hours, 2) if hours else None,
         "by_stake": by_stake,
     }
+
+
+# --- live session HUD (everything tracked in the current session, for the UI) ---
+
+def _session_villains(sid: int) -> list[dict]:
+    """Players read this session, with their standing dossier fields."""
+    rows = _c().execute(
+        "SELECT p.name AS name, p.category AS category, p.tendencies AS tendencies, "
+        "p.adjustment AS adjustment, "
+        "(SELECT note FROM player_reads r2 WHERE r2.player_id = p.id "
+        " AND r2.session_id = ? ORDER BY r2.id DESC LIMIT 1) AS last_note "
+        "FROM poker_players p "
+        "WHERE p.id IN (SELECT DISTINCT player_id FROM player_reads "
+        "               WHERE session_id = ? AND player_id IS NOT NULL) "
+        "ORDER BY p.updated_at DESC",
+        (sid, sid),
+    ).fetchall()
+    return [dict(r) for r in rows]
+
+
+def hud(session_id: int | None = None) -> dict | None:
+    """Everything tracked in the current (or given) session, for the live HUD.
+
+    Returns None when there's no session to show. The shape is presentation-ready:
+    header, stack (with sparkline series + live net), hands, villains seen, her
+    notes from the session window, and session stats.
+    """
+    s = get_session(session_id) if session_id is not None else live_session()
+    if not s:
+        return None
+    sid = s["id"]
+    log = stack_log(sid)
+    state = stack_state(sid)
+
+    hands = [
+        {"id": h["id"], "position": h.get("position"), "hole_cards": h.get("hole_cards"),
+         "board": h.get("board"), "result": h.get("result"), "tag": h.get("tag"),
+         "at": h.get("at")}
+        for h in list_hands(sid)
+    ]
+
+    # Notes she jotted during this session: journal/note entries since it started.
+    started = s.get("started_at") or ""
+    notes = [
+        {"created_at": j["created_at"], "kind": j["kind"], "content": j["content"]}
+        for j in memory.list_journal(kinds=("note", "journal"))
+        if (j["created_at"] or "") >= started
+    ][:20]
+
+    stats = session_stats(sid)
+    # Context: how Brian runs at these stakes overall (closed sessions).
+    ctx = running_stats(stakes=s.get("stakes")) if s.get("stakes") else {}
+
+    return {
+        "session": {
+            "id": sid, "venue": s.get("venue"), "stakes": s.get("stakes"),
+            "game": s.get("game"), "format": s.get("format"),
+            "status": s.get("status"), "started_at": s.get("started_at"),
+            "buy_in_total": s.get("buy_in_total"),
+        },
+        "stack": {
+            "current": state["current"], "buy_in": state["buy_in"], "net": state["net"],
+            "log": log,
+        },
+        "hands": hands,
+        "villains": _session_villains(sid),
+        "notes": notes,
+        "stats": {
+            "hands_logged": stats.get("hands_logged", 0),
+            "tags": stats.get("tags", {}),
+            "context_per_hour": ctx.get("per_hour"),
+        },
+    }