fix(bot): chat agent — ГРЛС excerpts in drug check, questions with alcohol answered, retry, clearer logs

Live run through the API (Andrey, real OpenRouter): onset questions now answered from the instruction
excerpt, «можно пиво?» reaches the agent although the check-in records alcohol, quit intent keeps the single
rule reaction, findings are mentioned only for intake/combination questions, one retry on a provider error,
provider error message logged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/llm/agent/providers.py

@@ -66,6 +66,12 @@ class OpenRouterProvider:
         except httpx.HTTPError as exc:
             raise ProviderError(type(exc).__name__) from exc
         if resp.status_code != 200:
+            # Provider error bodies are generic (no patient text) — log the message to make failures diagnosable.
+            try:
+                detail = str(resp.json().get("error", {}).get("message", ""))[:200]
+            except ValueError:
+                detail = ""
+            log.error("openrouter http %s: %s", resp.status_code, detail)
             raise ProviderError(f"http {resp.status_code}")
         try:
             msg = resp.json()["choices"][0]["message"]