fix: address review findings

- install.sh: verify SHA-256 checksum before installing binary
- install.sh: fallback to ~/.local/bin if /usr/local/bin not writable
- install.sh: use sed instead of grep for POSIX-safe JSON parsing
- release.yml: remove jq dependency, parse release ID with sed
- llm: make temperature configurable via --llm-temperature / LLM_TEMPERATURE
- llm: add WithTemperature builder method on Client
- llm: omit temperature from request when zero (uses server default)

llm/client.go

@@ -14,6 +14,7 @@ type Client struct {
 	BaseURL string
 	APIKey  string
 	Model   string
+	Temperature float64
 	HTTP    *http.Client
 }
 
@@ -27,6 +28,13 @@ func NewClient(baseURL, apiKey, model string) *Client {
 	}
 }
 
+// WithTemperature sets the temperature for LLM requests.
+// If not set (zero value), the server default is used.
+func (c *Client) WithTemperature(t float64) *Client {
+	c.Temperature = t
+	return c
+}
+
 // Message represents a chat message.
 type Message struct {
 	Role    string `json:"role"`
@@ -53,6 +61,7 @@ type ChatResponse struct {
 func (c *Client) Complete(messages []Message) (string, error) {
 	reqBody := ChatRequest{
 		Model:       c.Model,
+		Temperature: c.Temperature,
 		Messages:    messages,
 		
 	}