Optimize for Claude Agent SDK: Memory, context, and model selection

## Memory & Context Optimizations

### agent.py
- MAX_CONTEXT_MESSAGES: 10 → 20 (better conversation coherence)
- MEMORY_RESPONSE_PREVIEW_LENGTH: 200 → 500 (richer memory storage)
- MAX_CONVERSATION_HISTORY: 50 → 100 (longer session continuity)
- search_hybrid max_results: 2 → 5 (better memory recall)
- System prompt: Now mentions tool count and flat-rate subscription
- Memory format: Changed "User (username)/Agent" to "username/Garvis"

### llm_interface.py
- Added claude_agent_sdk model (Sonnet) to defaults
- Mode-based model selection:
  * Agent SDK → Sonnet (best quality, flat-rate)
  * Direct API → Haiku (cheapest, pay-per-token)
- Updated logging to show active model

## SOUL.md Rewrite

- Added Garvis identity (name, email, role)
- Listed all 17 tools (was missing 12 tools)
- Added "Critical Behaviors" section
- Emphasized flat-rate subscription benefits
- Clear instructions to always check user profiles

## Benefits

With flat-rate Agent SDK:
- ✅ Use Sonnet for better reasoning (was Haiku)
- ✅ 2x context messages (10 → 20)
- ✅ 2.5x memory results (2 → 5)
- ✅ 2.5x richer memory previews (200 → 500 chars)
- ✅ Bot knows its name and all capabilities
- ✅ Zero marginal cost for thoroughness

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

llm_interface.py

@@ -38,7 +38,8 @@ _USE_AGENT_SDK = os.getenv("USE_AGENT_SDK", "true").lower() == "true"
 
 # Default models by provider
 _DEFAULT_MODELS = {
-    "claude": "claude-haiku-4-5-20251001",  # 12x cheaper than Sonnet!
+    "claude": "claude-haiku-4-5-20251001",  # For Direct API (pay-per-token)
+    "claude_agent_sdk": "claude-sonnet-4-5-20250929",  # For Agent SDK (flat-rate subscription)
     "glm": "glm-4-plus",
 }
 
@@ -58,9 +59,9 @@ class LLMInterface:
         self.api_key = api_key or os.getenv(
             _API_KEY_ENV_VARS.get(provider, ""),
         )
-        self.model = _DEFAULT_MODELS.get(provider, "")
         self.client: Optional[Anthropic] = None
         self.agent_sdk: Optional[Any] = None
+        # Model will be set after determining mode
 
         # Determine mode (priority: direct API > legacy server > agent SDK)
         if provider == "claude":
@@ -82,16 +83,25 @@ class LLMInterface:
         # Usage tracking (disabled when using Agent SDK or legacy server)
         self.tracker = UsageTracker() if (track_usage and self.mode == "direct_api") else None
 
+        # Set model based on mode
+        if provider == "claude":
+            if self.mode == "agent_sdk":
+                self.model = _DEFAULT_MODELS.get("claude_agent_sdk", "claude-sonnet-4-5-20250929")
+            else:
+                self.model = _DEFAULT_MODELS.get(provider, "claude-haiku-4-5-20251001")
+        else:
+            self.model = _DEFAULT_MODELS.get(provider, "")
+
         # Initialize based on mode
         if provider == "claude":
             if self.mode == "agent_sdk":
-                print(f"[LLM] Using Claude Agent SDK (Pro subscription)")
+                print(f"[LLM] Using Claude Agent SDK (flat-rate subscription) with model: {self.model}")
                 self.agent_sdk = AgentSDK()
             elif self.mode == "direct_api":
-                print(f"[LLM] Using Direct API (pay-per-token)")
+                print(f"[LLM] Using Direct API (pay-per-token) with model: {self.model}")
                 self.client = Anthropic(api_key=self.api_key)
             elif self.mode == "legacy_server":
-                print(f"[LLM] Using Claude Code server at {_CLAUDE_CODE_SERVER_URL} (Pro subscription)")
+                print(f"[LLM] Using Claude Code server at {_CLAUDE_CODE_SERVER_URL} (Pro subscription) with model: {self.model}")
                 # Verify server is running
                 try:
                     response = requests.get(f"{_CLAUDE_CODE_SERVER_URL}/", timeout=2)