Integrate Bifrost LLM gateway, add test suite, implement memory pipeline

- Add Bifrost (maximhq/bifrost) as LLM gateway: all inference routes through
  bifrost:8080/v1 with retry logic and observability; VRAMManager keeps direct
  Ollama access for VRAM flush/prewarm operations
- Switch medium model from qwen3:4b to qwen2.5:1.5b (direct call, no tools)
  via _DirectModel wrapper; complex keeps create_deep_agent with qwen3:8b
- Implement out-of-agent memory pipeline: _retrieve_memories pre-fetches
  relevant context (injected into all tiers), _store_memory runs as background
  task after each reply writing to openmemory/Qdrant
- Add tests/unit/ with 133 tests covering router, channels, vram_manager,
  agent helpers; move integration test to tests/integration/
- Add bifrost-config.json with GPU Ollama (qwen2.5:0.5b/1.5b, qwen3:4b/8b,
  gemma3:4b) and CPU Ollama providers
- Integration test 28/29 pass (only grammy fails — no TELEGRAM_BOT_TOKEN)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bifrost-config.json

@@ -0,0 +1,58 @@
+{
+  "client": {
+    "drop_excess_requests": false
+  },
+  "providers": {
+    "ollama": {
+      "keys": [
+        {
+          "name": "ollama-gpu",
+          "value": "dummy",
+          "models": [
+            "qwen2.5:0.5b",
+            "qwen2.5:1.5b",
+            "qwen3:4b",
+            "gemma3:4b",
+            "qwen3:8b"
+          ],
+          "weight": 1.0
+        }
+      ],
+      "network_config": {
+        "base_url": "http://host.docker.internal:11436",
+        "default_request_timeout_in_seconds": 300,
+        "max_retries": 2,
+        "retry_backoff_initial_ms": 500,
+        "retry_backoff_max_ms": 10000
+      }
+    },
+    "ollama-cpu": {
+      "keys": [
+        {
+          "name": "ollama-cpu-key",
+          "value": "dummy",
+          "models": [
+            "gemma3:1b",
+            "qwen2.5:1.5b",
+            "qwen2.5:3b"
+          ],
+          "weight": 1.0
+        }
+      ],
+      "network_config": {
+        "base_url": "http://host.docker.internal:11435",
+        "default_request_timeout_in_seconds": 120,
+        "max_retries": 2,
+        "retry_backoff_initial_ms": 500,
+        "retry_backoff_max_ms": 10000
+      },
+      "custom_provider_config": {
+        "base_provider_type": "openai",
+        "allowed_requests": {
+          "chat_completion": true,
+          "chat_completion_stream": true
+        }
+      }
+    }
+  }
+}