feat: system logs page + dynamic IV watchlist with auto-add from cycle

Backend:
- DB: add system_logs table (level/source/cycle_id/ticker/message) and
  iv_watchlist table (ticker/added_by/is_active); seed builtin 18 tickers
- DBLogHandler attached at startup — all WARNING+ logs auto-persist to DB
- log_system_event() helper for structured manual events
- New router /api/logs: GET with filters (level, source, cycle_id, ticker,
  date range), GET /sources, GET /cycles for dropdowns, DELETE /clear
- iv_watchlist now read from DB instead of hardcoded constant; options_vol
  watchlist/refresh/bootstrap endpoints all use get_watchlist_tickers()
- New endpoints: POST/DELETE /options-vol/watchlist-tickers/{ticker} to
  add/remove tickers; adding triggers background 1-year bootstrap
- auto_cycle: after log_trade_entries(), auto-detect new underlying proxies
  not yet in watchlist, add them and bootstrap their IV history

Frontend:
- New page SystemLogs (/logs): log table with level/source/cycle/ticker/date
  filters, color-coded rows, expandable JSON details, auto-refresh 30s
- Options Lab: WatchlistManager section — add ticker input, chip list with
  builtin/auto/manual color coding, remove button for non-builtins
- Sidebar: Logs Système nav link (ScrollText icon)
- useApi: useSystemLogs, useLogSources, useLogCycles, useClearLogs,
  useWatchlistTickers, useAddWatchlistTicker, useRemoveWatchlistTicker

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/database.py

@@ -342,10 +342,31 @@ def init_db():
         created_at TEXT DEFAULT (datetime('now'))
     )""")
 
+    c.execute("""CREATE TABLE IF NOT EXISTS iv_watchlist (
+        ticker TEXT PRIMARY KEY,
+        added_date TEXT NOT NULL DEFAULT (date('now')),
+        added_by TEXT DEFAULT 'builtin',
+        is_active INTEGER DEFAULT 1
+    )""")
+
+    c.execute("""CREATE TABLE IF NOT EXISTS system_logs (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        ts TEXT NOT NULL DEFAULT (datetime('now')),
+        level TEXT NOT NULL,
+        source TEXT,
+        cycle_id TEXT,
+        ticker TEXT,
+        message TEXT NOT NULL,
+        details TEXT
+    )""")
+
     try:
         c.execute("CREATE INDEX IF NOT EXISTS idx_kb_category ON knowledge_base(category, status)")
         c.execute("CREATE INDEX IF NOT EXISTS idx_rs_version ON reasoning_state(version DESC)")
         c.execute("CREATE UNIQUE INDEX IF NOT EXISTS idx_iv_history_ticker_date ON iv_history(ticker, recorded_date)")
+        c.execute("CREATE INDEX IF NOT EXISTS idx_syslog_ts ON system_logs(ts DESC)")
+        c.execute("CREATE INDEX IF NOT EXISTS idx_syslog_level ON system_logs(level, ts DESC)")
+        c.execute("CREATE INDEX IF NOT EXISTS idx_syslog_cycle ON system_logs(cycle_id, ts DESC)")
     except Exception:
         pass
 
@@ -361,6 +382,18 @@ def init_db():
                 (_key, _val)
             )
 
+    # Seed built-in watchlist tickers (idempotent)
+    _builtin_tickers = [
+        "SPY", "QQQ", "GLD", "SLV", "USO", "BNO", "UNG",
+        "XLE", "UUP", "TLT", "GDX", "EWJ", "FEZ",
+        "XOM", "CVX", "LMT", "RTX", "BA",
+    ]
+    for _t in _builtin_tickers:
+        c.execute(
+            "INSERT OR IGNORE INTO iv_watchlist (ticker, added_by) VALUES (?, 'builtin')",
+            (_t,)
+        )
+
     conn.commit()
     conn.close()
 
@@ -1637,6 +1670,134 @@ def get_iv_history(ticker: str, days: int = 90) -> List[Dict]:
     return [dict(r) for r in rows]
 
 
+# ── IV Watchlist ──────────────────────────────────────────────────────────────
+
+def get_watchlist_tickers() -> List[str]:
+    conn = get_conn()
+    rows = conn.execute(
+        "SELECT ticker FROM iv_watchlist WHERE is_active=1 ORDER BY added_by='builtin' DESC, added_date ASC"
+    ).fetchall()
+    conn.close()
+    return [r["ticker"] for r in rows]
+
+
+def get_watchlist_entries() -> List[Dict]:
+    conn = get_conn()
+    rows = conn.execute(
+        "SELECT ticker, added_date, added_by, is_active FROM iv_watchlist ORDER BY added_by, ticker"
+    ).fetchall()
+    conn.close()
+    return [dict(r) for r in rows]
+
+
+def add_watchlist_ticker(ticker: str, added_by: str = "manual") -> bool:
+    """Add ticker to watchlist. Returns True if newly inserted, False if already existed."""
+    conn = get_conn()
+    existing = conn.execute("SELECT ticker, is_active FROM iv_watchlist WHERE ticker=?", (ticker.upper(),)).fetchone()
+    if existing:
+        if not existing["is_active"]:
+            conn.execute("UPDATE iv_watchlist SET is_active=1, added_by=? WHERE ticker=?", (added_by, ticker.upper()))
+            conn.commit()
+            conn.close()
+            return True
+        conn.close()
+        return False
+    conn.execute(
+        "INSERT INTO iv_watchlist (ticker, added_date, added_by) VALUES (?, date('now'), ?)",
+        (ticker.upper(), added_by)
+    )
+    conn.commit()
+    conn.close()
+    return True
+
+
+def remove_watchlist_ticker(ticker: str) -> bool:
+    conn = get_conn()
+    conn.execute("UPDATE iv_watchlist SET is_active=0 WHERE ticker=?", (ticker.upper(),))
+    changed = conn.total_changes > 0
+    conn.commit()
+    conn.close()
+    return changed
+
+
+# ── System Logs ───────────────────────────────────────────────────────────────
+
+def log_system_event(
+    level: str,
+    source: str,
+    message: str,
+    cycle_id: Optional[str] = None,
+    ticker: Optional[str] = None,
+    details: Optional[Dict] = None,
+) -> None:
+    try:
+        conn = get_conn()
+        conn.execute(
+            """INSERT INTO system_logs (level, source, cycle_id, ticker, message, details)
+               VALUES (?, ?, ?, ?, ?, ?)""",
+            (
+                level.upper(),
+                source,
+                cycle_id,
+                ticker.upper() if ticker else None,
+                message,
+                json.dumps(details, default=str) if details else None,
+            ),
+        )
+        conn.commit()
+        conn.close()
+    except Exception:
+        pass  # Never raise from logging
+
+
+def get_system_logs(
+    level: Optional[str] = None,
+    source: Optional[str] = None,
+    cycle_id: Optional[str] = None,
+    ticker: Optional[str] = None,
+    date_from: Optional[str] = None,
+    date_to: Optional[str] = None,
+    limit: int = 300,
+) -> List[Dict]:
+    conn = get_conn()
+    clauses = []
+    params: List[Any] = []
+    if level:
+        clauses.append("level = ?")
+        params.append(level.upper())
+    if source:
+        clauses.append("source LIKE ?")
+        params.append(f"%{source}%")
+    if cycle_id:
+        clauses.append("cycle_id = ?")
+        params.append(cycle_id)
+    if ticker:
+        clauses.append("ticker = ?")
+        params.append(ticker.upper())
+    if date_from:
+        clauses.append("ts >= ?")
+        params.append(date_from)
+    if date_to:
+        clauses.append("ts <= ?")
+        params.append(date_to + "T23:59:59")
+    where = ("WHERE " + " AND ".join(clauses)) if clauses else ""
+    rows = conn.execute(
+        f"SELECT id, ts, level, source, cycle_id, ticker, message, details FROM system_logs {where} ORDER BY ts DESC LIMIT ?",
+        params + [limit],
+    ).fetchall()
+    conn.close()
+    return [dict(r) for r in rows]
+
+
+def clear_system_logs(older_than_days: int = 30) -> int:
+    conn = get_conn()
+    conn.execute(f"DELETE FROM system_logs WHERE ts < datetime('now', '-{older_than_days} days')")
+    deleted = conn.total_changes
+    conn.commit()
+    conn.close()
+    return deleted
+
+
 # ── Knowledge Base Decay ──────────────────────────────────────────────────────
 
 def decay_kb_confidence() -> int: