refactor(config): drop env-based config (except OPENAI_API_KEY)

- Switch to config-file-only; only OPENAI_API_KEY read from env.\n- llm: replace env autodetect with Config + NewFromConfig; add newOpenAI/newOllama.\n- lsp: NewServer now accepts injected llm.Client.\n- cli: remove env overrides; extend appConfig with provider-specific fields; build client from config + OPENAI_API_KEY.\n- docs: update README (config-only, defaults to OpenAI, minimal example); simplify flags table.\n- add config.json.example.\n- prompts: enforce ;text; (no spaces) and add ;;text; to remove entire line; tests added.

3 files changed, 74 insertions, 82 deletions

diff --git a/internal/llm/ollama.go b/internal/llm/ollama.go
index 495b5c2..db3e06b 100644
--- a/internal/llm/ollama.go
+++ b/internal/llm/ollama.go
@@ -7,7 +7,6 @@ import (
     "errors"
     "fmt"
     "net/http"
-    "os"
     "strings"
     "time"
 
@@ -21,22 +20,16 @@ type ollamaClient struct {
     defaultModel string
 }
 
-func newOllamaFromEnv() Client {
-    // Prefer OLLAMA_BASE_URL, fall back to OLLAMA_HOST, then default.
-    base := strings.TrimSpace(os.Getenv("OLLAMA_BASE_URL"))
-    if base == "" {
-        base = strings.TrimSpace(os.Getenv("OLLAMA_HOST"))
+func newOllama(baseURL, model string) Client {
+    if strings.TrimSpace(baseURL) == "" {
+        baseURL = "http://localhost:11434"
     }
-    if base == "" {
-        base = "http://localhost:11434"
-    }
-    model := strings.TrimSpace(os.Getenv("OLLAMA_MODEL"))
-    if model == "" {
+    if strings.TrimSpace(model) == "" {
         model = "qwen2.5-coder:latest"
     }
     return &ollamaClient{
         httpClient:   &http.Client{Timeout: 30 * time.Second},
-        baseURL:      strings.TrimRight(base, "/"),
+        baseURL:      strings.TrimRight(baseURL, "/"),
         defaultModel: model,
     }
 }
diff --git a/internal/llm/openai.go b/internal/llm/openai.go
index dbcee4d..03e894a 100644
--- a/internal/llm/openai.go
+++ b/internal/llm/openai.go
@@ -7,7 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"os"
+	"strings"
 	"time"
 
 	"hexai/internal/logging"
@@ -15,27 +15,27 @@ import (
 
 // openAIClient implements Client against OpenAI's Chat Completions API.
 type openAIClient struct {
-    httpClient   *http.Client
-    apiKey       string
-    baseURL      string
-    defaultModel string
+	httpClient   *http.Client
+	apiKey       string
+	baseURL      string
+	defaultModel string
 }
 
 // Colors and base styling are provided by logging.go
 
-func newOpenAIFromEnv(apiKey string) Client {
-	base := os.Getenv("OPENAI_BASE_URL")
-	if base == "" {
-		base = "https://api.openai.com/v1"
+// newOpenAI constructs an OpenAI client using explicit configuration values.
+// The apiKey may be empty; calls will fail until a valid key is supplied.
+func newOpenAI(baseURL, model, apiKey string) Client {
+	if strings.TrimSpace(baseURL) == "" {
+		baseURL = "https://api.openai.com/v1"
 	}
-	model := os.Getenv("OPENAI_MODEL")
-	if model == "" {
-		model = "gpt-4o-mini"
+	if strings.TrimSpace(model) == "" {
+		model = "gpt-4.1"
 	}
 	return &openAIClient{
 		httpClient:   &http.Client{Timeout: 30 * time.Second},
 		apiKey:       apiKey,
-		baseURL:      base,
+		baseURL:      baseURL,
 		defaultModel: model,
 	}
 }
@@ -82,10 +82,10 @@ func (c *openAIClient) Chat(ctx context.Context, messages []Message, opts ...Req
 		o.Model = c.defaultModel
 	}
 	start := time.Now()
-    logging.Logf("llm/openai ", "chat start model=%s temp=%.2f max_tokens=%d stop=%d messages=%d", o.Model, o.Temperature, o.MaxTokens, len(o.Stop), len(messages))
+	logging.Logf("llm/openai ", "chat start model=%s temp=%.2f max_tokens=%d stop=%d messages=%d", o.Model, o.Temperature, o.MaxTokens, len(o.Stop), len(messages))
 	for i, m := range messages {
-        // Sending context (cyan)
-        logging.Logf("llm/openai ", "msg[%d] role=%s size=%d preview=%s%s%s", i, m.Role, len(m.Content), logging.AnsiCyan, logging.PreviewForLog(m.Content), logging.AnsiBase)
+		// Sending context (cyan)
+		logging.Logf("llm/openai ", "msg[%d] role=%s size=%d preview=%s%s%s", i, m.Role, len(m.Content), logging.AnsiCyan, logging.PreviewForLog(m.Content), logging.AnsiBase)
 	}
 	req := oaChatRequest{Model: o.Model}
 	req.Messages = make([]oaMessage, len(messages))
@@ -108,7 +108,7 @@ func (c *openAIClient) Chat(ctx context.Context, messages []Message, opts ...Req
 		return "", err
 	}
 	endpoint := c.baseURL + "/chat/completions"
-    logging.Logf("llm/openai ", "POST %s", endpoint)
+	logging.Logf("llm/openai ", "POST %s", endpoint)
 	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
 	if err != nil {
 		c.logf("new request error: %v", err)
@@ -118,34 +118,34 @@ func (c *openAIClient) Chat(ctx context.Context, messages []Message, opts ...Req
 	httpReq.Header.Set("Authorization", "Bearer "+c.apiKey)
 
 	resp, err := c.httpClient.Do(httpReq)
-    if err != nil {
-        logging.Logf("llm/openai ", "%shttp error after %s: %v%s", logging.AnsiRed, time.Since(start), err, logging.AnsiBase)
-        return "", err
-    }
+	if err != nil {
+		logging.Logf("llm/openai ", "%shttp error after %s: %v%s", logging.AnsiRed, time.Since(start), err, logging.AnsiBase)
+		return "", err
+	}
 	defer resp.Body.Close()
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		var apiErr oaChatResponse
 		_ = json.NewDecoder(resp.Body).Decode(&apiErr)
-        if apiErr.Error != nil && apiErr.Error.Message != "" {
-            logging.Logf("llm/openai ", "%sapi error status=%d type=%s msg=%s duration=%s%s", logging.AnsiRed, resp.StatusCode, apiErr.Error.Type, apiErr.Error.Message, time.Since(start), logging.AnsiBase)
-            return "", fmt.Errorf("openai error: %s (status %d)", apiErr.Error.Message, resp.StatusCode)
-        }
-        logging.Logf("llm/openai ", "%shttp non-2xx status=%d duration=%s%s", logging.AnsiRed, resp.StatusCode, time.Since(start), logging.AnsiBase)
-        return "", fmt.Errorf("openai http error: status %d", resp.StatusCode)
-    }
+		if apiErr.Error != nil && apiErr.Error.Message != "" {
+			logging.Logf("llm/openai ", "%sapi error status=%d type=%s msg=%s duration=%s%s", logging.AnsiRed, resp.StatusCode, apiErr.Error.Type, apiErr.Error.Message, time.Since(start), logging.AnsiBase)
+			return "", fmt.Errorf("openai error: %s (status %d)", apiErr.Error.Message, resp.StatusCode)
+		}
+		logging.Logf("llm/openai ", "%shttp non-2xx status=%d duration=%s%s", logging.AnsiRed, resp.StatusCode, time.Since(start), logging.AnsiBase)
+		return "", fmt.Errorf("openai http error: status %d", resp.StatusCode)
+	}
 	var out oaChatResponse
-    if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
-        logging.Logf("llm/openai ", "%sdecode error after %s: %v%s", logging.AnsiRed, time.Since(start), err, logging.AnsiBase)
-        return "", err
-    }
-    if len(out.Choices) == 0 {
-        logging.Logf("llm/openai ", "%sno choices returned duration=%s%s", logging.AnsiRed, time.Since(start), logging.AnsiBase)
-        return "", errors.New("openai: no choices returned")
-    }
-    content := out.Choices[0].Message.Content
-    // Received context (green)
-    logging.Logf("llm/openai ", "success choice=0 finish=%s size=%d preview=%s%s%s duration=%s", out.Choices[0].FinishReason, len(content), logging.AnsiGreen, logging.PreviewForLog(content), logging.AnsiBase, time.Since(start))
-    return content, nil
+	if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
+		logging.Logf("llm/openai ", "%sdecode error after %s: %v%s", logging.AnsiRed, time.Since(start), err, logging.AnsiBase)
+		return "", err
+	}
+	if len(out.Choices) == 0 {
+		logging.Logf("llm/openai ", "%sno choices returned duration=%s%s", logging.AnsiRed, time.Since(start), logging.AnsiBase)
+		return "", errors.New("openai: no choices returned")
+	}
+	content := out.Choices[0].Message.Content
+	// Received context (green)
+	logging.Logf("llm/openai ", "success choice=0 finish=%s size=%d preview=%s%s%s duration=%s", out.Choices[0].FinishReason, len(content), logging.AnsiGreen, logging.PreviewForLog(content), logging.AnsiBase, time.Since(start))
+	return content, nil
 }
 
 // small helper to keep return type consistent
@@ -161,5 +161,5 @@ func trimPreview(s string, n int) string {
 }
 
 // Provider metadata
-func (c *openAIClient) Name() string          { return "openai" }
-func (c *openAIClient) DefaultModel() string  { return c.defaultModel }
+func (c *openAIClient) Name() string         { return "openai" }
+func (c *openAIClient) DefaultModel() string { return c.defaultModel }
diff --git a/internal/llm/provider.go b/internal/llm/provider.go
index f7dad31..c7367ed 100644
--- a/internal/llm/provider.go
+++ b/internal/llm/provider.go
@@ -3,7 +3,6 @@ package llm
 import (
     "context"
     "errors"
-    "os"
     "strings"
 )
 
@@ -42,34 +41,34 @@ func WithStop(stop ...string) RequestOption {
 	return func(o *Options) { o.Stop = append([]string{}, stop...) }
 }
 
-// NewDefault returns the default provider using environment configuration.
-// Selection order:
-// 1) HEXAI_LLM_PROVIDER=openai|ollama
-// 2) If OPENAI_API_KEY is set -> OpenAI
-// 3) If any OLLAMA_* vars are set -> Ollama
-func NewDefault() (Client, error) {
-    // Explicit provider selection
-    if p := strings.ToLower(strings.TrimSpace(os.Getenv("HEXAI_LLM_PROVIDER"))); p != "" {
-        switch p {
-        case "openai":
-            apiKey := os.Getenv("OPENAI_API_KEY")
-            if apiKey == "" {
-                return nil, errors.New("OPENAI_API_KEY is not set")
-            }
-            return newOpenAIFromEnv(apiKey), nil
-        case "ollama":
-            return newOllamaFromEnv(), nil
-        default:
-            return nil, errors.New("unknown HEXAI_LLM_PROVIDER: " + p)
-        }
-    }
+// Config defines provider configuration read from the Hexai config file.
+type Config struct {
+    Provider       string
+    // OpenAI options
+    OpenAIBaseURL  string
+    OpenAIModel    string
+    // Ollama options
+    OllamaBaseURL  string
+    OllamaModel    string
+}
 
-    // Auto-detect
-    if apiKey := os.Getenv("OPENAI_API_KEY"); apiKey != "" {
-        return newOpenAIFromEnv(apiKey), nil
+// NewFromConfig creates an LLM client using only the supplied configuration.
+// The OpenAI API key is supplied separately and may be read from the environment
+// by the caller; other environment-based configuration is not used.
+func NewFromConfig(cfg Config, openAIAPIKey string) (Client, error) {
+    p := strings.ToLower(strings.TrimSpace(cfg.Provider))
+    if p == "" {
+        p = "openai"
     }
-    if os.Getenv("OLLAMA_BASE_URL") != "" || os.Getenv("OLLAMA_HOST") != "" || os.Getenv("OLLAMA_MODEL") != "" {
-        return newOllamaFromEnv(), nil
+    switch p {
+    case "openai":
+        if strings.TrimSpace(openAIAPIKey) == "" {
+            return nil, errors.New("missing OPENAI_API_KEY for provider openai")
+        }
+        return newOpenAI(cfg.OpenAIBaseURL, cfg.OpenAIModel, openAIAPIKey), nil
+    case "ollama":
+        return newOllama(cfg.OllamaBaseURL, cfg.OllamaModel), nil
+    default:
+        return nil, errors.New("unknown LLM provider: " + p)
     }
-    return nil, errors.New("no LLM provider configured (set OPENAI_API_KEY or HEXAI_LLM_PROVIDER/OLLAMA_*)")
 }