feat: add context.Context + unexport client fields

REVIEW.md findings 1-4, 14:
- All Gitea client methods now accept context.Context as first param
- All LLM client methods now accept context.Context as first param
- Use http.NewRequestWithContext for cancellation/timeout support
- Main uses 3-minute timeout context for all operations
- Unexport Client struct fields (baseURL, token, apiKey, etc.)
- Use bytes.NewReader instead of strings.NewReader(string(...))

llm/client.go

@@ -2,6 +2,7 @@ package llm
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -11,26 +12,26 @@ import (
 
 // Client calls an OpenAI-compatible chat completion API.
 type Client struct {
-	BaseURL string
-	APIKey  string
-	Model   string
-	Temperature float64
-	HTTP    *http.Client
+	baseURL     string
+	apiKey      string
+	model       string
+	temperature float64
+	http        *http.Client
 }
 
 // NewClient creates a new LLM client.
 func NewClient(baseURL, apiKey, model string) *Client {
 	return &Client{
-		BaseURL: strings.TrimRight(baseURL, "/"),
-		APIKey:  apiKey,
-		Model:   model,
-		HTTP:    &http.Client{},
+		baseURL: strings.TrimRight(baseURL, "/"),
+		apiKey:  apiKey,
+		model:   model,
+		http:    &http.Client{},
 	}
 }
 
 // WithTemperature sets the temperature for LLM requests (0 = omit, uses server default).
 func (c *Client) WithTemperature(t float64) *Client {
-	c.Temperature = t
+	c.temperature = t
 	return c
 }
 
@@ -57,12 +58,11 @@ type ChatResponse struct {
 }
 
 // Complete sends a chat completion request and returns the assistant's response content.
-func (c *Client) Complete(messages []Message) (string, error) {
+func (c *Client) Complete(ctx context.Context, messages []Message) (string, error) {
 	reqBody := ChatRequest{
-		Model:       c.Model,
-		Temperature: c.Temperature,
+		Model:       c.model,
+		Temperature: c.temperature,
 		Messages:    messages,
-		
 	}
 
 	data, err := json.Marshal(reqBody)
@@ -70,15 +70,15 @@ func (c *Client) Complete(messages []Message) (string, error) {
 		return "", fmt.Errorf("marshal request: %w", err)
 	}
 
-	url := c.BaseURL + "/chat/completions"
-	req, err := http.NewRequest("POST", url, bytes.NewReader(data))
+	url := c.baseURL + "/chat/completions"
+	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(data))
 	if err != nil {
 		return "", fmt.Errorf("create request: %w", err)
 	}
-	req.Header.Set("Authorization", "Bearer "+c.APIKey)
+	req.Header.Set("Authorization", "Bearer "+c.apiKey)
 	req.Header.Set("Content-Type", "application/json")
 
-	resp, err := c.HTTP.Do(req)
+	resp, err := c.http.Do(req)
 	if err != nil {
 		return "", fmt.Errorf("LLM request: %w", err)
 	}