Add local PromptKit backend configuration

internal/core/config/validation_contract_test.go

@@ -93,6 +93,73 @@ func TestValidatePromptKitSourcesAreMutuallyExclusive(t *testing.T) {
 	assertValidationContains(t, cfg, "promptkit profile_dir and profile_file are mutually exclusive")
 }
 
+func TestValidatePromptKitLocalBackendEndpoints(t *testing.T) {
+	tests := []struct {
+		name          string
+		endpoint      string
+		profileSource PromptKitConfig
+	}{
+		{
+			name:          "HTTP endpoint with path and profile directory",
+			endpoint:      "http://localhost:8000/v1",
+			profileSource: PromptKitConfig{ProfileDir: "./profiles"},
+		},
+		{
+			name:          "case-insensitive HTTPS endpoint and profile file",
+			endpoint:      "HTTPS://inference.example.test/api",
+			profileSource: PromptKitConfig{ProfileFile: "./profiles.yml"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := Default()
+			cfg.PromptKit = tt.profileSource
+			cfg.PromptKit.LocalBackend = &PromptKitLocalBackendConfig{
+				Endpoint:         tt.endpoint,
+				ConcurrencyLimit: 2,
+			}
+			if err := cfg.Validate(); err != nil {
+				t.Fatalf("Validate() error = %v", err)
+			}
+		})
+	}
+}
+
+func TestValidatePromptKitLocalBackendRejectsInvalidValues(t *testing.T) {
+	tests := []struct {
+		name             string
+		endpoint         string
+		concurrencyLimit int
+		want             string
+	}{
+		{name: "blank endpoint", endpoint: "   ", want: "promptkit.local_backend.endpoint"},
+		{name: "relative URL", endpoint: "localhost:8000/v1", want: "promptkit.local_backend.endpoint"},
+		{name: "unsupported scheme", endpoint: "ftp://localhost/model", want: "promptkit.local_backend.endpoint"},
+		{name: "missing host", endpoint: "http:///v1", want: "promptkit.local_backend.endpoint"},
+		{name: "user information", endpoint: "http://user:secret@localhost/v1", want: "promptkit.local_backend.endpoint"},
+		{name: "query", endpoint: "http://localhost/v1?model=example", want: "promptkit.local_backend.endpoint"},
+		{name: "empty query", endpoint: "http://localhost/v1?", want: "promptkit.local_backend.endpoint"},
+		{name: "fragment", endpoint: "http://localhost/v1#model", want: "promptkit.local_backend.endpoint"},
+		{name: "empty fragment", endpoint: "http://localhost/v1#", want: "promptkit.local_backend.endpoint"},
+		{
+			name:             "negative concurrency",
+			endpoint:         "http://localhost:8000/v1",
+			concurrencyLimit: -1,
+			want:             "promptkit.local_backend.concurrency_limit",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := Default()
+			cfg.PromptKit.LocalBackend = &PromptKitLocalBackendConfig{
+				Endpoint:         tt.endpoint,
+				ConcurrencyLimit: tt.concurrencyLimit,
+			}
+			assertValidationContains(t, cfg, tt.want)
+		})
+	}
+}
+
 func TestValidateStateSurfaceRules(t *testing.T) {
 	tests := []struct {
 		name  string