refactor: differentiate reference marker handling between stream and non-stream modes

- Stream: strip both and [reference:N] markers to prevent
  leaking partial link metadata during incremental output
- Non-stream: convert citation/reference markers to Markdown links for
  Claude Messages, Gemini generateContent, and OpenAI Chat/Responses
- Remove StripReferenceMarkers option from call sites; behavior is now
  determined automatically by stream vs non-stream context
- Extend JS runtime stripReferenceMarkersText() to also match [citation:N]
- Add tests for streaming marker stripping and non-stream link conversion

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/httpapi/openai/shared/stream_accumulator.go

@@ -89,11 +89,11 @@ func (a *StreamAccumulator) applyTextPart(text string) StreamPartDelta {
 	}
 	a.RawText.WriteString(rawTrimmed)
 	delta := StreamPartDelta{Type: "text", RawText: rawTrimmed}
-	cleanedText := CleanVisibleOutput(rawTrimmed, a.StripReferenceMarkers)
-	if a.SearchEnabled && sse.IsCitation(cleanedText) {
+	if a.SearchEnabled && sse.IsCitation(rawTrimmed) {
 		delta.CitationOnly = true
 		return delta
 	}
+	cleanedText := CleanVisibleOutput(rawTrimmed, a.StripReferenceMarkers)
 	trimmed := sse.TrimContinuationOverlapFromBuilder(&a.Text, cleanedText)
 	if trimmed == "" {
 		return delta

internal/httpapi/openai/shared/stream_accumulator_test.go

@@ -95,3 +95,21 @@ func TestStreamAccumulatorSuppressesCitationTextWhenSearchEnabled(t *testing.T)
 		t.Fatalf("visible text = %q", got)
 	}
 }
+
+func TestStreamAccumulatorStripsInlineCitationAndReferenceMarkers(t *testing.T) {
+	acc := StreamAccumulator{SearchEnabled: true, StripReferenceMarkers: true}
+	result := acc.Apply(sse.LineResult{
+		Parsed: true,
+		Parts:  []sse.ContentPart{{Type: "text", Text: "广州天气[citation:1] 多云[reference:0]"}},
+	})
+
+	if !result.ContentSeen {
+		t.Fatalf("expected marker chunk to mark upstream content")
+	}
+	if got := acc.Text.String(); got != "广州天气 多云" {
+		t.Fatalf("visible text = %q", got)
+	}
+	if len(result.Parts) != 1 || result.Parts[0].VisibleText != "广州天气 多云" {
+		t.Fatalf("unexpected parts: %#v", result.Parts)
+	}
+}