fix: increase output token limit to prevent response truncation

- Add MAX_OUTPUT_TOKENS constant set to 32,768 (Gemini 2.5 Pro's limit)
- Update all tools and chat handler to use MAX_OUTPUT_TOKENS
- Add comprehensive tests for output token configuration
- Update README with configuration details and system prompt docs

This fixes the issue where Gemini responses were being cut off at 8192 tokens,
causing Claude to repeatedly ask for the same analysis.

Fixes #1

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tests/test_config.py

@@ -2,9 +2,10 @@
 Tests for configuration
 """
 
-from config import (DEFAULT_MODEL, MAX_CONTEXT_TOKENS, TEMPERATURE_ANALYTICAL,
-                    TEMPERATURE_BALANCED, TEMPERATURE_CREATIVE, TOOL_TRIGGERS,
-                    __author__, __updated__, __version__)
+from config import (DEFAULT_MODEL, MAX_CONTEXT_TOKENS, MAX_OUTPUT_TOKENS,
+                    TEMPERATURE_ANALYTICAL, TEMPERATURE_BALANCED,
+                    TEMPERATURE_CREATIVE, TOOL_TRIGGERS, __author__,
+                    __updated__, __version__)
 
 
 class TestConfig:
@@ -20,6 +21,7 @@ class TestConfig:
         """Test model configuration"""
         assert DEFAULT_MODEL == "gemini-2.5-pro-preview-06-05"
         assert MAX_CONTEXT_TOKENS == 1_000_000
+        assert MAX_OUTPUT_TOKENS == 32_768
 
     def test_temperature_defaults(self):
         """Test temperature constants"""