fix(provider): add insecure_skip_verify option for HTTP providers

Add insecure_skip_verify configuration option to ModelConfig to allow
skipping TLS certificate verification for development/testing environments.

This fixes SSL certificate verification issues when using volcengine
and other providers in environments with missing or outdated CA certificates
(e.g., Android Termux).

Changes:
- Add InsecureSkipVerify field to ModelConfig in config.go
- Add WithInsecureSkipVerify option function in openai_compat/provider.go
- Add NewHTTPProviderWithOptions function in http_provider.go
- Update factory_provider.go to pass insecure_skip_verify to all HTTP providers

Usage example in config.json:
{
  "model_list": [{
    "model_name": "doubao",
    "model": "volcengine/doubao-pro",
    "api_key": "your-api-key",
    "insecure_skip_verify": true
  }]
}

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

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

pkg/config/config.go

@@ -563,6 +563,9 @@ type ModelConfig struct {
 	MaxTokensField string `json:"max_tokens_field,omitempty"` // Field name for max tokens (e.g., "max_completion_tokens")
 	RequestTimeout int    `json:"request_timeout,omitempty"`
 	ThinkingLevel  string `json:"thinking_level,omitempty"` // Extended thinking: off|low|medium|high|xhigh|adaptive
+
+	// TLS configuration
+	InsecureSkipVerify bool `json:"insecure_skip_verify,omitempty"` // Skip TLS certificate verification (for development/testing only)
 }
 
 // Validate checks if the ModelConfig has all required fields.

pkg/providers/factory_provider.go

@@ -84,12 +84,13 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 		if apiBase == "" {
 			apiBase = getDefaultAPIBase(protocol)
 		}
-		return NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
+		return NewHTTPProviderWithOptions(
 			cfg.APIKey,
 			apiBase,
 			cfg.Proxy,
 			cfg.MaxTokensField,
 			cfg.RequestTimeout,
+			cfg.InsecureSkipVerify,
 		), modelID, nil
 
 	case "litellm", "openrouter", "groq", "zhipu", "gemini", "nvidia",
@@ -104,12 +105,13 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 		if apiBase == "" {
 			apiBase = getDefaultAPIBase(protocol)
 		}
-		return NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
+		return NewHTTPProviderWithOptions(
 			cfg.APIKey,
 			apiBase,
 			cfg.Proxy,
 			cfg.MaxTokensField,
 			cfg.RequestTimeout,
+			cfg.InsecureSkipVerify,
 		), modelID, nil
 
 	case "anthropic":
@@ -129,12 +131,13 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 		if cfg.APIKey == "" {
 			return nil, "", fmt.Errorf("api_key is required for anthropic protocol (model: %s)", cfg.Model)
 		}
-		return NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
+		return NewHTTPProviderWithOptions(
 			cfg.APIKey,
 			apiBase,
 			cfg.Proxy,
 			cfg.MaxTokensField,
 			cfg.RequestTimeout,
+			cfg.InsecureSkipVerify,
 		), modelID, nil
 
 	case "antigravity":

pkg/providers/http_provider.go

@@ -30,6 +30,21 @@ func NewHTTPProviderWithMaxTokensField(apiKey, apiBase, proxy, maxTokensField st
 func NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
 	apiKey, apiBase, proxy, maxTokensField string,
 	requestTimeoutSeconds int,
+) *HTTPProvider {
+	return NewHTTPProviderWithOptions(
+		apiKey,
+		apiBase,
+		proxy,
+		maxTokensField,
+		requestTimeoutSeconds,
+		false,
+	)
+}
+
+func NewHTTPProviderWithOptions(
+	apiKey, apiBase, proxy, maxTokensField string,
+	requestTimeoutSeconds int,
+	insecureSkipVerify bool,
 ) *HTTPProvider {
 	return &HTTPProvider{
 		delegate: openai_compat.NewProvider(
@@ -38,6 +53,7 @@ func NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
 			proxy,
 			openai_compat.WithMaxTokensField(maxTokensField),
 			openai_compat.WithRequestTimeout(time.Duration(requestTimeoutSeconds)*time.Second),
+			openai_compat.WithInsecureSkipVerify(insecureSkipVerify),
 		),
 	}
 }

pkg/providers/openai_compat/provider.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -54,6 +55,24 @@ func WithRequestTimeout(timeout time.Duration) Option {
 	}
 }
 
+func WithInsecureSkipVerify(skip bool) Option {
+	return func(p *Provider) {
+		if skip {
+			transport := p.httpClient.Transport
+			if transport == nil {
+				transport = &http.Transport{}
+			}
+			if tr, ok := transport.(*http.Transport); ok {
+				if tr.TLSClientConfig == nil {
+					tr.TLSClientConfig = &tls.Config{}
+				}
+				tr.TLSClientConfig.InsecureSkipVerify = true
+				p.httpClient.Transport = tr
+			}
+		}
+	}
+}
+
 func NewProvider(apiKey, apiBase, proxy string, opts ...Option) *Provider {
 	client := &http.Client{
 		Timeout: defaultRequestTimeout,