chore: scaffold uv project, config, personas, risk, model profiles

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016DvdRZkyCy9NJpHYDdPqmS

config/risk.py

@@ -0,0 +1,24 @@
+"""Risk guardrails. Generous-but-present defaults for a paper account.
+
+These are enforced programmatically in ``execution/guardrails.py`` — the LLM's
+requested sizing and stop/take levels are inputs that get clamped here, never trusted.
+"""
+
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+class RiskConfig(BaseModel):
+    max_position_pct: float = 0.10  # cap per single position, % of equity
+    max_symbol_exposure_pct: float = 0.15  # aggregate cap per ticker across all agents
+    max_trades_per_agent: int = 3
+    max_trades_per_day: int = 8
+    allow_shorts: bool = True  # shorts enabled; persona prompts decide when to use them
+    default_stop_pct: float = 0.07
+    default_take_pct: float = 0.15
+    min_price: float = 3.0  # skip sub-$3 names
+    max_price: float | None = None
+
+
+DEFAULT_RISK = RiskConfig()