feat: render hybrid recent context

docs/prompt-compatibility.md

@@ -299,25 +299,30 @@ OpenAI 的文件上传现在不再是“只传文件本体”的通用路径，
 - 全局 completion runtime 应用点：
   [internal/completionruntime/nonstream.go](../internal/completionruntime/nonstream.go)
 
-当前输入转文件启用并触发时，上传的历史文件名由 `filename_policy` 决定，文件内容是完整 `messages` 上下文；`natural_context` 策略会生成自然化 conversation context（不再注入文件边界标签）：
+当前输入转文件启用并触发时，上传的历史文件名由 `filename_policy` 决定，文件内容来自完整 `messages` 上下文；默认 `hybrid_recent` 策略会生成带语义压缩的 conversation context（不再注入文件边界标签）：
 
 ```text
 [uploaded filename]: conversation-notes-a1b2c3.txt
 # Conversation Context
-This note captures the working conversation state for the current request.
+This note summarizes earlier context and preserves the most recent turns needed for the current reply.
 
-## Conversation
+## Current Task
+最新用户请求原文。
 
-1. System guidance:
-...
+## Non-Negotiable Instructions
 
-2. User:
-...
+- system / developer 约束摘要。
+
+## Earlier Context Summary
+
+- 较早历史的短摘要、已确认决策、已完成工具结果。
+
+## Recent Exact Context
 
-3. Assistant:
+1. User:
 ...
 
-4. Tool result (name: search, call id: call-1):
+2. Tool result (name: search, call id: call-1):
 ...
 ```
 

internal/httpapi/openai/history/current_input_cache_test.go

@@ -218,7 +218,7 @@ func TestApplyCurrentInputFileGoldenTranscriptStability(t *testing.T) {
 	if len(ds.uploads) != 2 {
 		t.Fatalf("expected history and tools uploads, got %d", len(ds.uploads))
 	}
-	const wantHistory = "# Conversation Context\nThis note captures the working conversation state for the current request.\n\n## Conversation\n\n1. System guidance:\nsystem rule\n\n2. User:\nsearch docs\n"
+	const wantHistory = "# Conversation Context\nThis note summarizes earlier context and preserves the most recent turns needed for the current reply.\n\n## Current Task\nsearch docs\n\n## Non-Negotiable Instructions\n\n- system rule\n\n## Recent Exact Context\n\n1. System guidance:\nsystem rule\n\n2. User:\nsearch docs\n"
 	if got := string(ds.uploads[0].Data); got != wantHistory {
 		t.Fatalf("history transcript mismatch:\n--- got ---\n%s\n--- want ---\n%s", got, wantHistory)
 	}

internal/httpapi/openai/history/current_input_file.go

@@ -205,7 +205,7 @@ func currentInputFilenamePolicy(store CurrentInputConfigReader) string {
 func currentInputContextStrategy(store CurrentInputConfigReader) string {
 	reader, ok := store.(currentInputContextStrategyReader)
 	if !ok {
-		return "natural_context"
+		return "hybrid_recent"
 	}
 	return config.NormalizeContextEngineStrategy(reader.ContextEngineStrategy())
 }

internal/promptcompat/history_transcript.go

@@ -11,6 +11,15 @@ const historyTranscriptTitle = "# DS2API_HISTORY.txt"
 const historyTranscriptSummary = "Prior conversation history and tool progress."
 const naturalContextTitle = "# Conversation Context"
 const naturalContextSummary = "This note captures the working conversation state for the current request."
+const hybridRecentExactEntries = 8
+const hybridSummaryMaxEntries = 12
+const hybridSummarySnippetRunes = 260
+
+type contextHistoryEntry struct {
+	Role    string
+	Label   string
+	Content string
+}
 
 func BuildOpenAIHistoryTranscript(messages []any) string {
 	return buildOpenAIHistoryTranscript(messages)
@@ -33,8 +42,12 @@ func BuildOpenAICurrentInputContextTranscriptWithStrategy(messages []any, strate
 	switch strings.ToLower(strings.TrimSpace(strategy)) {
 	case "raw_transcript":
 		return buildOpenAIHistoryTranscript(messages)
-	default:
+	case "natural_context":
 		return buildOpenAINaturalContextTranscript(messages)
+	case "context_capsule":
+		return buildOpenAIHybridRecentContextTranscript(messages, false)
+	default:
+		return buildOpenAIHybridRecentContextTranscript(messages, true)
 	}
 }
 
@@ -75,7 +88,8 @@ func buildOpenAIHistoryTranscript(messages []any) string {
 }
 
 func buildOpenAINaturalContextTranscript(messages []any) string {
-	if len(messages) == 0 {
+	entries := collectContextHistoryEntries(messages)
+	if len(entries) == 0 {
 		return ""
 	}
 	var b strings.Builder
@@ -86,6 +100,53 @@ func buildOpenAINaturalContextTranscript(messages []any) string {
 	b.WriteString("## Conversation\n\n")
 
 	entry := 0
+	for _, item := range entries {
+		entry++
+		fmt.Fprintf(&b, "%d. %s:\n%s\n\n", entry, item.Label, item.Content)
+	}
+
+	transcript := strings.TrimSpace(b.String())
+	if transcript == "" {
+		return ""
+	}
+	return transcript + "\n"
+}
+
+func buildOpenAIHybridRecentContextTranscript(messages []any, includeRecentExact bool) string {
+	entries := collectContextHistoryEntries(messages)
+	if len(entries) == 0 {
+		return ""
+	}
+	var b strings.Builder
+	b.WriteString(naturalContextTitle)
+	b.WriteString("\n")
+	b.WriteString("This note summarizes earlier context and preserves the most recent turns needed for the current reply.")
+	b.WriteString("\n\n")
+
+	if latest := latestUserContextEntry(entries); latest.Content != "" {
+		b.WriteString("## Current Task\n")
+		b.WriteString(latest.Content)
+		b.WriteString("\n\n")
+	}
+
+	writeSystemGuidanceSection(&b, entries)
+	writeEarlierSummarySection(&b, entries, includeRecentExact)
+	if includeRecentExact {
+		writeRecentExactSection(&b, entries)
+	}
+
+	transcript := strings.TrimSpace(b.String())
+	if transcript == "" {
+		return ""
+	}
+	return transcript + "\n"
+}
+
+func collectContextHistoryEntries(messages []any) []contextHistoryEntry {
+	if len(messages) == 0 {
+		return nil
+	}
+	entries := make([]contextHistoryEntry, 0, len(messages))
 	for _, raw := range messages {
 		msg, ok := raw.(map[string]any)
 		if !ok {
@@ -96,15 +157,96 @@ func buildOpenAINaturalContextTranscript(messages []any) string {
 		if content == "" {
 			continue
 		}
-		entry++
-		fmt.Fprintf(&b, "%d. %s:\n%s\n\n", entry, naturalRoleLabelForHistory(role, msg), content)
+		entries = append(entries, contextHistoryEntry{
+			Role:    role,
+			Label:   naturalRoleLabelForHistory(role, msg),
+			Content: content,
+		})
 	}
+	return entries
+}
 
-	transcript := strings.TrimSpace(b.String())
-	if transcript == "" {
-		return ""
+func latestUserContextEntry(entries []contextHistoryEntry) contextHistoryEntry {
+	for i := len(entries) - 1; i >= 0; i-- {
+		if entries[i].Role == "user" {
+			return entries[i]
+		}
 	}
-	return transcript + "\n"
+	return contextHistoryEntry{}
+}
+
+func writeSystemGuidanceSection(b *strings.Builder, entries []contextHistoryEntry) {
+	wroteHeader := false
+	for _, entry := range entries {
+		if entry.Role != "system" {
+			continue
+		}
+		if !wroteHeader {
+			b.WriteString("## Non-Negotiable Instructions\n\n")
+			wroteHeader = true
+		}
+		b.WriteString("- ")
+		b.WriteString(oneLineSnippet(entry.Content, hybridSummarySnippetRunes))
+		b.WriteString("\n")
+	}
+	if wroteHeader {
+		b.WriteString("\n")
+	}
+}
+
+func writeEarlierSummarySection(b *strings.Builder, entries []contextHistoryEntry, includeRecentExact bool) {
+	summaryEnd := len(entries)
+	if includeRecentExact {
+		summaryEnd -= hybridRecentExactEntries
+		if summaryEnd < 0 {
+			summaryEnd = 0
+		}
+	}
+	if summaryEnd <= 0 {
+		return
+	}
+	start := 0
+	if summaryEnd > hybridSummaryMaxEntries {
+		start = summaryEnd - hybridSummaryMaxEntries
+	}
+	b.WriteString("## Earlier Context Summary\n\n")
+	if start > 0 {
+		fmt.Fprintf(b, "- %d older messages omitted after summarization.\n", start)
+	}
+	for _, entry := range entries[start:summaryEnd] {
+		if entry.Role == "system" {
+			continue
+		}
+		fmt.Fprintf(b, "- %s: %s\n", entry.Label, oneLineSnippet(entry.Content, hybridSummarySnippetRunes))
+	}
+	b.WriteString("\n")
+}
+
+func writeRecentExactSection(b *strings.Builder, entries []contextHistoryEntry) {
+	start := 0
+	if len(entries) > hybridRecentExactEntries {
+		start = len(entries) - hybridRecentExactEntries
+	}
+	recent := entries[start:]
+	if len(recent) == 0 {
+		return
+	}
+	b.WriteString("## Recent Exact Context\n\n")
+	for i, entry := range recent {
+		fmt.Fprintf(b, "%d. %s:\n%s\n\n", i+1, entry.Label, entry.Content)
+	}
+}
+
+func oneLineSnippet(text string, maxRunes int) string {
+	text = strings.Join(strings.Fields(strings.TrimSpace(text)), " ")
+	if maxRunes <= 0 {
+		return text
+	}
+	runes := []rune(text)
+	if len(runes) <= maxRunes {
+		return text
+	}
+	return string(runes[:maxRunes]) + "..."
 }
 
 func buildOpenAIHistoryEntry(role string, msg map[string]any) string {

internal/promptcompat/history_transcript_test.go

@@ -0,0 +1,62 @@
+package promptcompat
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestBuildOpenAICurrentInputContextTranscriptHybridRecentCompressesOlderMessages(t *testing.T) {
+	messages := []any{
+		map[string]any{"role": "system", "content": "keep user constraints exact"},
+	}
+	for i := 1; i <= 12; i++ {
+		messages = append(messages, map[string]any{"role": "user", "content": fmt.Sprintf("older detail %02d with repeated background", i)})
+		messages = append(messages, map[string]any{"role": "assistant", "content": fmt.Sprintf("assistant response %02d with repeated explanation", i)})
+	}
+	messages = append(messages, map[string]any{"role": "user", "content": "latest request must be exact"})
+
+	got := BuildOpenAICurrentInputContextTranscriptWithStrategy(messages, "hybrid_recent")
+	for _, want := range []string{
+		"# Conversation Context",
+		"## Current Task\nlatest request must be exact",
+		"## Non-Negotiable Instructions",
+		"## Earlier Context Summary",
+		"## Recent Exact Context",
+		"latest request must be exact",
+	} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("expected hybrid context to contain %q, got %q", want, got)
+		}
+	}
+	if strings.Contains(got, "DS2API") {
+		t.Fatalf("hybrid context should not expose implementation terms, got %q", got)
+	}
+	if strings.Contains(got, "older detail 01 with repeated background\n\n") {
+		t.Fatalf("oldest messages should be summarized, not kept as exact turns: %q", got)
+	}
+}
+
+func TestBuildOpenAICurrentInputContextTranscriptStrategyShapes(t *testing.T) {
+	messages := []any{
+		map[string]any{"role": "system", "content": "system rule"},
+		map[string]any{"role": "user", "content": "first turn"},
+		map[string]any{"role": "assistant", "content": "first answer"},
+		map[string]any{"role": "user", "content": "latest request"},
+	}
+
+	raw := BuildOpenAICurrentInputContextTranscriptWithStrategy(messages, "raw_transcript")
+	if !strings.Contains(raw, "# DS2API_HISTORY.txt") || !strings.Contains(raw, "=== 1. SYSTEM ===") {
+		t.Fatalf("expected raw transcript shape, got %q", raw)
+	}
+
+	natural := BuildOpenAICurrentInputContextTranscriptWithStrategy(messages, "natural_context")
+	if !strings.Contains(natural, "## Conversation") || strings.Contains(natural, "Earlier Context Summary") {
+		t.Fatalf("expected full natural context shape, got %q", natural)
+	}
+
+	capsule := BuildOpenAICurrentInputContextTranscriptWithStrategy(messages, "context_capsule")
+	if !strings.Contains(capsule, "## Current Task") || strings.Contains(capsule, "## Recent Exact Context") {
+		t.Fatalf("expected context capsule without recent exact section, got %q", capsule)
+	}
+}