refactor(watcher): extract config diff helpers

Break out config diffing, hashing, and OpenAI compatibility utilities into a dedicated diff package, update watcher to consume them, and add comprehensive tests for diff logic and watcher behavior.

internal/watcher/diff/openai_compat_test.go

@@ -0,0 +1,113 @@
+package diff
+
+import (
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+)
+
+func TestDiffOpenAICompatibility(t *testing.T) {
+	oldList := []config.OpenAICompatibility{
+		{
+			Name: "provider-a",
+			APIKeyEntries: []config.OpenAICompatibilityAPIKey{
+				{APIKey: "key-a"},
+			},
+			Models: []config.OpenAICompatibilityModel{
+				{Name: "m1"},
+			},
+		},
+	}
+	newList := []config.OpenAICompatibility{
+		{
+			Name: "provider-a",
+			APIKeyEntries: []config.OpenAICompatibilityAPIKey{
+				{APIKey: "key-a"},
+				{APIKey: "key-b"},
+			},
+			Models: []config.OpenAICompatibilityModel{
+				{Name: "m1"},
+				{Name: "m2"},
+			},
+			Headers: map[string]string{"X-Test": "1"},
+		},
+		{
+			Name:          "provider-b",
+			APIKeyEntries: []config.OpenAICompatibilityAPIKey{{APIKey: "key-b"}},
+		},
+	}
+
+	changes := DiffOpenAICompatibility(oldList, newList)
+	expectContains(t, changes, "provider added: provider-b (api-keys=1, models=0)")
+	expectContains(t, changes, "provider updated: provider-a (api-keys 1 -> 2, models 1 -> 2, headers updated)")
+}
+
+func TestDiffOpenAICompatibility_RemovedAndUnchanged(t *testing.T) {
+	oldList := []config.OpenAICompatibility{
+		{
+			Name:          "provider-a",
+			APIKeyEntries: []config.OpenAICompatibilityAPIKey{{APIKey: "key-a"}},
+			Models:        []config.OpenAICompatibilityModel{{Name: "m1"}},
+		},
+	}
+	newList := []config.OpenAICompatibility{
+		{
+			Name:          "provider-a",
+			APIKeyEntries: []config.OpenAICompatibilityAPIKey{{APIKey: "key-a"}},
+			Models:        []config.OpenAICompatibilityModel{{Name: "m1"}},
+		},
+	}
+	if changes := DiffOpenAICompatibility(oldList, newList); len(changes) != 0 {
+		t.Fatalf("expected no changes, got %v", changes)
+	}
+
+	newList = nil
+	changes := DiffOpenAICompatibility(oldList, newList)
+	expectContains(t, changes, "provider removed: provider-a (api-keys=1, models=1)")
+}
+
+func TestOpenAICompatKeyFallbacks(t *testing.T) {
+	entry := config.OpenAICompatibility{
+		BaseURL: "http://base",
+		Models:  []config.OpenAICompatibilityModel{{Alias: "alias-only"}},
+	}
+	key, label := openAICompatKey(entry, 0)
+	if key != "base:http://base" || label != "http://base" {
+		t.Fatalf("expected base key, got %s/%s", key, label)
+	}
+
+	entry.BaseURL = ""
+	key, label = openAICompatKey(entry, 1)
+	if key != "alias:alias-only" || label != "alias-only" {
+		t.Fatalf("expected alias fallback, got %s/%s", key, label)
+	}
+
+	entry.Models = nil
+	key, label = openAICompatKey(entry, 2)
+	if key != "index:2" || label != "entry-3" {
+		t.Fatalf("expected index fallback, got %s/%s", key, label)
+	}
+}
+
+func TestCountOpenAIModelsSkipsBlanks(t *testing.T) {
+	models := []config.OpenAICompatibilityModel{
+		{Name: "m1"},
+		{Name: ""},
+		{Alias: ""},
+		{Name: " "},
+		{Alias: "a1"},
+	}
+	if got := countOpenAIModels(models); got != 2 {
+		t.Fatalf("expected 2 counted models, got %d", got)
+	}
+}
+
+func TestOpenAICompatKeyUsesModelNameWhenAliasEmpty(t *testing.T) {
+	entry := config.OpenAICompatibility{
+		Models: []config.OpenAICompatibilityModel{{Name: "model-name"}},
+	}
+	key, label := openAICompatKey(entry, 5)
+	if key != "alias:model-name" || label != "model-name" {
+		t.Fatalf("expected model-name fallback, got %s/%s", key, label)
+	}
+}