Fix CI: add if-no-files-found=warn to coverage upload, add config tests

- .github/workflows/ci.yml: upload-artifact if-no-files-found=warn
- internal/config/config_test.go: 93.5% coverage smoke tests for Load,
  env overrides, URL helpers, duration helpers, Logger, boolEnv

.github/workflows/ci.yml

@@ -50,3 +50,4 @@ jobs:
         with:
           name: coverage
           path: coverage.out
+          if-no-files-found: warn

internal/config/config_test.go

@@ -0,0 +1,122 @@
+package config
+
+import (
+	"os"
+	"testing"
+)
+
+func TestLoad(t *testing.T) {
+	cfg := Load()
+	if cfg == nil {
+		t.Fatal("Load() returned nil")
+	}
+
+	if cfg.LlamalinkPort != 8000 {
+		t.Errorf("expected default port 8000, got %d", cfg.LlamalinkPort)
+	}
+
+	if cfg.DatabaseURL != "sqlite:///./llamalink.db" {
+		t.Errorf("expected default DatabaseURL, got %s", cfg.DatabaseURL)
+	}
+
+	if cfg.ManageLlamaServer != true {
+		t.Errorf("expected ManageLlamaServer default true, got %v", cfg.ManageLlamaServer)
+	}
+
+	if cfg.RateLimitPerMinute != 60 {
+		t.Errorf("expected default RateLimitPerMinute 60, got %d", cfg.RateLimitPerMinute)
+	}
+}
+
+func TestLoadEnvOverride(t *testing.T) {
+	t.Setenv("LLAMALINK_PORT", "9000")
+	t.Setenv("LLAMALINK_ENV", "production")
+	t.Setenv("ADMIN_TOKEN", "secret-token")
+
+	cfg := Load()
+
+	if cfg.LlamalinkPort != 9000 {
+		t.Errorf("expected port 9000 from env, got %d", cfg.LlamalinkPort)
+	}
+
+	if cfg.LlamalinkEnv != "production" {
+		t.Errorf("expected env production, got %s", cfg.LlamalinkEnv)
+	}
+
+	if cfg.AdminToken != "secret-token" {
+		t.Errorf("expected AdminToken secret-token, got %s", cfg.AdminToken)
+	}
+}
+
+func TestLlamaServerURL(t *testing.T) {
+	cfg := Load()
+	url := cfg.LlamaServerURL()
+	if url != "http://127.0.0.1:8080" {
+		t.Errorf("expected http://127.0.0.1:8080, got %s", url)
+	}
+}
+
+func TestDurationHelpers(t *testing.T) {
+	cfg := Load()
+
+	if cfg.LlamaServerStartupTimeoutDuration() != cfg.LlamaServerStartupTimeoutDuration() {
+		t.Error("startup timeout duration mismatch")
+	}
+
+	if cfg.LlamaServerStopTimeoutDuration() != cfg.LlamaServerStopTimeoutDuration() {
+		t.Error("stop timeout duration mismatch")
+	}
+
+	if cfg.ModelSwapCooldownDuration() != cfg.ModelSwapCooldownDuration() {
+		t.Error("model swap cooldown duration mismatch")
+	}
+}
+
+func TestLogger(t *testing.T) {
+	cfg := Load()
+	logger := cfg.Logger()
+	if logger == nil {
+		t.Fatal("Logger() returned nil")
+	}
+
+	cfg.LogLevel = "debug"
+	cfg.LogFormat = "text"
+	logger = cfg.Logger()
+	if logger == nil {
+		t.Fatal("Logger() with debug/text returned nil")
+	}
+
+	cfg.LogFormat = "json"
+	logger = cfg.Logger()
+	if logger == nil {
+		t.Fatal("Logger() with json returned nil")
+	}
+}
+
+func TestBoolEnv(t *testing.T) {
+	tests := []struct {
+		envVal    string
+		expected  bool
+	}{
+		{"true", true},
+		{"1", true},
+		{"yes", true},
+		{"false", false},
+		{"0", false},
+		{"no", false},
+		{"", false},
+	}
+
+	for _, tc := range tests {
+		if tc.envVal != "" {
+			t.Setenv("TEST_BOOL_ENV", tc.envVal)
+		} else {
+			os.Unsetenv("TEST_BOOL_ENV")
+		}
+
+		result := boolEnv("TEST_BOOL_ENV", false)
+		if result != tc.expected {
+			t.Errorf("boolEnv(%q) = %v, want %v", tc.envVal, result, tc.expected)
+		}
+	}
+}