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.

1 files changed, 27 insertions, 28 deletions

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_*)")
 }