inject created timestamp for OpenAI spec compatibility

OpenWebUI was failing with 'NoneType' errors because it expects a
'created' field on all chat and embedding responses. OpenAI always
includes this unix-timestamp field in both streaming chunks and
non-streaming responses.

- Inject 'created' into non-streaming responses if the upstream
  didn't provide one (chat + embeddings)
- Inject 'created' into every streaming SSE chunk if missing
- Add 'created' to Anthropic synthetic streaming chunks and
  non-streaming translated responses

backend/internal/api/chat.go

@@ -90,9 +90,10 @@ func (a *API) chatCompletions(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	a.Limiter.RecordTokens(entry.Address, resp.Usage.TotalTokens)
+	respBody := injectCreated(resp.Body)
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(resp.StatusCode)
-	_, _ = w.Write(resp.Body)
+	_, _ = w.Write(respBody)
 
 	completion := extractCompletion(resp.Body)
 	a.logRequest(r, key, entry, address, resp.StatusCode, false, resp.Usage, "", start, nil, messages, completion)
@@ -122,6 +123,7 @@ func (a *API) streamChat(w http.ResponseWriter, r *http.Request, cc providers.Ch
 
 	var ttft *int
 	var sb strings.Builder
+	created := time.Now().Unix()
 	for {
 		ev, err := stream.Recv()
 		if errors.Is(err, io.EOF) {
@@ -136,7 +138,7 @@ func (a *API) streamChat(w http.ResponseWriter, r *http.Request, cc providers.Ch
 		}
 		// Accumulate assistant content from delta chunks.
 		sb.WriteString(extractDelta(ev.Data))
-		_, _ = fmt.Fprintf(w, "data: %s\n\n", ev.Data)
+		_, _ = fmt.Fprintf(w, "data: %s\n\n", injectCreatedChunk(ev.Data, created))
 		if flusher != nil {
 			flusher.Flush()
 		}
@@ -263,3 +265,34 @@ func clientIP(r *http.Request) string {
 	}
 	return host
 }
+
+// injectCreated ensures a non-streaming response has a "created" timestamp.
+// If the upstream already provided one, it is preserved.
+func injectCreated(body []byte) []byte {
+	var obj map[string]any
+	if json.Unmarshal(body, &obj) == nil {
+		if _, ok := obj["created"]; ok {
+			return body // upstream already set it
+		}
+		obj["created"] = time.Now().Unix()
+		if out, err := json.Marshal(obj); err == nil {
+			return out
+		}
+	}
+	return body // fall back to raw body on any error
+}
+
+// injectCreatedChunk ensures a streaming SSE chunk has a "created" timestamp.
+func injectCreatedChunk(data []byte, created int64) []byte {
+	var obj map[string]any
+	if json.Unmarshal(data, &obj) == nil {
+		if _, ok := obj["created"]; ok {
+			return data // upstream already set it
+		}
+		obj["created"] = created
+		if out, err := json.Marshal(obj); err == nil {
+			return out
+		}
+	}
+	return data // fall back to raw chunk on any error
+}

backend/internal/api/embeddings.go

@@ -71,7 +71,7 @@ func (a *API) embeddings(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(resp.StatusCode)
-	_, _ = w.Write(resp.Body)
+	_, _ = w.Write(injectCreated(resp.Body))
 
 	a.logRequest(r, key, entry, address, resp.StatusCode, false, resp.Usage, "", start, nil, nil, "")
 }

backend/internal/providers/anthropic/stream.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"io"
+	"time"
 
 	"git.govekar.net/LovroG05/localmodelroutex/internal/providers"
 )
@@ -16,6 +17,7 @@ type stream struct {
 	br           *bufio.Reader
 	model        string
 	id           string
+	created      int64
 	roleSent     bool
 	finished     bool
 	finishReason string
@@ -24,10 +26,11 @@ type stream struct {
 
 func newStream(rc io.ReadCloser, model string) *stream {
 	return &stream{
-		rc:    rc,
-		br:    bufio.NewReaderSize(rc, 64*1024),
-		model: model,
-		id:    "chatcmpl-stream",
+		rc:      rc,
+		br:      bufio.NewReaderSize(rc, 64*1024),
+		model:   model,
+		id:      "chatcmpl-stream",
+		created: time.Now().Unix(),
 	}
 }
 
@@ -143,6 +146,7 @@ func (s *stream) chunk(delta map[string]any, finish *string, usage map[string]an
 	obj := map[string]any{
 		"id":      s.id,
 		"object":  "chat.completion.chunk",
+		"created": s.created,
 		"model":   s.model,
 		"choices": []any{choice},
 	}

backend/internal/providers/anthropic/translate.go

@@ -3,6 +3,7 @@ package anthropic
 import (
 	"encoding/json"
 	"strings"
+	"time"
 
 	"git.govekar.net/LovroG05/localmodelroutex/internal/providers"
 )
@@ -246,9 +247,10 @@ func translateResponse(body []byte, model string) ([]byte, providers.Usage) {
 		message["tool_calls"] = toolCalls
 	}
 	resp := map[string]any{
-		"id":     ar.ID,
-		"object": "chat.completion",
-		"model":  model,
+		"id":      ar.ID,
+		"object":  "chat.completion",
+		"created": time.Now().Unix(),
+		"model":   model,
 		"choices": []any{map[string]any{
 			"index":         0,
 			"message":       message,