Update memory provider to use Gemini 2.5 Flash (#10)

Gemini 2.0 models are deprecated.

See https://ai.google.dev/gemini-api/docs/models#previous_models

Author: z4y4ts

src/memory_bench/memory/mem0.py

@@ -14,7 +14,7 @@
 
 class Mem0MemoryProvider(MemoryProvider):
     name = "mem0"
-    description = "Agentic memory with Gemini 2.0 Flash for reflective extraction + local Qdrant store."
+    description = "Agentic memory with Gemini 2.5 Flash for reflective extraction + local Qdrant store."
     kind = "local"
     provider = "mem0"
     variant = "local"
@@ -36,7 +36,7 @@ def _build_memory(self, qdrant_path: str) -> Memory:
             {
                 "llm": {
                     "provider": "gemini",
-                    "config": {"model": "gemini-2.0-flash", "temperature": 0.0},
+                    "config": {"model": "gemini-2.5-flash", "temperature": 0.0},
                 },
                 "embedder": {
                     "provider": "huggingface",