feat(kevin_bridge): blocklist + daily risk counters

services/kevin_signal_bridge/blocklist.py

@@ -0,0 +1,37 @@
+"""Redis-backed per-symbol blocklist with TTL.
+
+Set on AVOID mentions. Subsequent BUY mention on the same symbol clears
+the entry (handled by the strategy callsite, not here).
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+class KevinBlocklist:
+    _KEY_PREFIX = "kevin:blocked:"
+
+    def __init__(self, redis: Any) -> None:
+        self.redis = redis
+
+    async def add(self, symbol: str, ttl_days: int) -> None:
+        await self.redis.set(
+            f"{self._KEY_PREFIX}{symbol}",
+            "1",
+            ex=ttl_days * 86400,
+        )
+
+    async def remove(self, symbol: str) -> None:
+        await self.redis.delete(f"{self._KEY_PREFIX}{symbol}")
+
+    async def is_blocked(self, symbol: str) -> bool:
+        return bool(await self.redis.exists(f"{self._KEY_PREFIX}{symbol}"))
+
+    async def active_set(self) -> set[str]:
+        keys = await self.redis.keys(f"{self._KEY_PREFIX}*")
+        out: set[str] = set()
+        for k in keys:
+            key_str = k.decode() if isinstance(k, bytes) else k
+            out.add(key_str.replace(self._KEY_PREFIX, ""))
+        return out