feat(docker): Add temperature and base_url parameters for LLM configuration. ref #1035

Implement hierarchical configuration for LLM parameters with support for:
  - Temperature control (0.0-2.0) to adjust response creativity
  - Custom base_url for proxy servers and alternative endpoints
  - 4-tier priority: request params > provider env > global env > defaults

  Add helper functions in utils.py, update API schemas and handlers,
  support environment variables (LLM_TEMPERATURE, OPENAI_TEMPERATURE, etc.),
  and provide comprehensive documentation with examples.

deploy/docker/.llm.env.example

@@ -10,4 +10,23 @@ GEMINI_API_TOKEN=your_gemini_key_here
 # Optional: Override the default LLM provider
 # Examples: "openai/gpt-4", "anthropic/claude-3-opus", "deepseek/chat", etc.
 # If not set, uses the provider specified in config.yml (default: openai/gpt-4o-mini)
-# LLM_PROVIDER=anthropic/claude-3-opus
+# LLM_PROVIDER=anthropic/claude-3-opus
+
+# Optional: Global LLM temperature setting (0.0-2.0)
+# Controls randomness in responses. Lower = more focused, Higher = more creative
+# LLM_TEMPERATURE=0.7
+
+# Optional: Global custom API base URL
+# Use this to point to custom endpoints or proxy servers
+# LLM_BASE_URL=https://api.custom.com/v1
+
+# Optional: Provider-specific temperature overrides
+# These take precedence over the global LLM_TEMPERATURE
+# OPENAI_TEMPERATURE=0.5
+# ANTHROPIC_TEMPERATURE=0.3
+# GROQ_TEMPERATURE=0.8
+
+# Optional: Provider-specific base URL overrides
+# Use for provider-specific proxy endpoints
+# OPENAI_BASE_URL=https://custom-openai.company.com/v1
+# GROQ_BASE_URL=https://custom-groq.company.com/v1