feat: adopt per-bot account api key for gateway attribution and improve post distinctness

- Add `account_api_key` field to `BotState` and `_adopt_account_api_key()` method that fetches the bot's own `users.api_key` from its profile JSON after auth, switching `LLMClient` to use it instead of the shared bootstrap key, routing gateway spend through the bot's user identity
- Replace `interleave_by_author` with a simpler greedy algorithm that picks the first row whose owner differs from the last picked, removing the multi-queue priority logic
- Extend `_ai_quota` response with `unlimited`, `requests`, and `last_used` fields sourced from new `user_spend_24h()` analytics helper
- Pass `recent_post_titles` from `BotState` into `LLMClient.generate_post()` and add a `distinct_rule` prompt instructing the model to avoid repeating framing, examples, or opinions from the bot's last six posts
- Remove early-return dedup check in `ArticleRegistry.admit` that skipped articles already held by the same bot owner, allowing re-admission under a different category
- Render bot username as a clickable link with avatar in the admin bots table

devplacepy/routers/profile/usage.py

@@ -3,6 +3,7 @@
 import logging
 
 from devplacepy.services.manager import service_manager
+from devplacepy.services.openai_gateway.analytics import user_spend_24h
 
 logger = logging.getLogger(__name__)
 
@@ -15,13 +16,21 @@ def _ai_quota(
         return None
     try:
         limit = devii.daily_limit_for("user", is_admin)
-        spent = devii.spent_24h("user", user_uid)
         turns = devii.hub().ledger.turns_24h("user", user_uid)
     except Exception:
         logger.exception("Failed to compute AI quota for %s", user_uid)
         return None
-    used_pct = round(min(100.0, spent / limit * 100), 1) if limit > 0 else 0.0
-    quota = {"used_pct": used_pct, "turns": turns}
+    gateway = user_spend_24h(user_uid)
+    spent = gateway["spent_usd"]
+    unlimited = limit <= 0
+    used_pct = 0.0 if unlimited else round(min(100.0, spent / limit * 100), 1)
+    quota = {
+        "used_pct": used_pct,
+        "unlimited": unlimited,
+        "turns": turns,
+        "requests": gateway["requests"],
+        "last_used": gateway["last_used"],
+    }
     if include_cost:
         quota["spent_usd"] = round(spent, 4)
         quota["limit_usd"] = round(limit, 2)