Refactor VNDB Telegram Bot

- Remove config.py and integrate environment variable handling directly in docker-compose.yml.
- Delete detailed_handlers.py and replace with simplified command handlers.
- Update requirements.txt to use aiogram and httpx instead of python-telegram-bot and requests.
- Remove test_bot.py and utils.py, consolidating functionality into new VNDBClient class.
- Implement VNDBClient for API interactions, simplifying query methods for visual novels, characters, and releases.
- Clean up docker-compose.yml for improved readability and maintainability.

vndb.py

@@ -0,0 +1,50 @@
+import httpx
+
+
+class VNDBClient:
+    def __init__(self, base_url):
+        self.base = base_url.rstrip("/")
+        self.client = httpx.AsyncClient(timeout=10)
+
+    async def _post(self, endpoint, payload):
+        try:
+            r = await self.client.post(f"{self.base}/{endpoint}", json=payload)
+
+            if r.status_code != 200:
+                return None
+
+            data = r.json()
+            return data.get("results", [])
+        except Exception:
+            return None
+
+    async def search_vn(self, query):
+        return await self._post("vn", {
+            "filters": ["search", "=", query],
+            "fields": "id,title,original,released,rating,votecount",
+            "results": 5
+        })
+
+    async def get_vn(self, vid):
+        res = await self._post("vn", {
+            "filters": ["id", "=", vid],
+            "fields": "id,title,original,released,rating,votecount",
+            "results": 1
+        })
+        return res[0] if res else None
+
+    async def get_char(self, cid):
+        res = await self._post("character", {
+            "filters": ["id", "=", cid],
+            "fields": "id,name,original",
+            "results": 1
+        })
+        return res[0] if res else None
+
+    async def get_release(self, rid):
+        res = await self._post("release", {
+            "filters": ["id", "=", rid],
+            "fields": "id,title,released",
+            "results": 1
+        })
+        return res[0] if res else None