fix(clean): correct project-tech field references and add sync vs clean disambiguation

- Fix Step 4.3: project.features → project.development_index,
  project.statistics → project._metadata
- Add project-guidelines.json learnings cleanup on session deletion
- Add sync vs clean disambiguation table explaining write vs reclaim

ccw/frontend/src/components/shared/ConversationCard.tsx

@@ -75,20 +75,24 @@ function formatDuration(ms: number): string {
 }
 
 /**
- * Get time ago string
+ * Hook to get localized time ago string
  */
-function getTimeAgo(dateString: string): string {
-  const date = new Date(dateString);
-  const now = new Date();
-  const seconds = Math.floor((now.getTime() - date.getTime()) / 1000);
+function useTimeAgo() {
+  const { formatMessage } = useIntl();
 
-  if (seconds < 60) return 'just now';
-  const minutes = Math.floor(seconds / 60);
-  if (minutes < 60) return `${minutes}m ago`;
-  const hours = Math.floor(minutes / 60);
-  if (hours < 24) return `${hours}h ago`;
-  const days = Math.floor(hours / 24);
-  return `${days}d ago`;
+  return React.useCallback((dateString: string): string => {
+    const date = new Date(dateString);
+    const now = new Date();
+    const seconds = Math.floor((now.getTime() - date.getTime()) / 1000);
+
+    if (seconds < 60) return formatMessage({ id: 'common.time.justNow' });
+    const minutes = Math.floor(seconds / 60);
+    if (minutes < 60) return formatMessage({ id: 'common.time.minutesAgo' }, { count: minutes });
+    const hours = Math.floor(minutes / 60);
+    if (hours < 24) return formatMessage({ id: 'common.time.hoursAgo' }, { count: hours });
+    const days = Math.floor(hours / 24);
+    return formatMessage({ id: 'common.time.daysAgo' }, { count: days });
+  }, [formatMessage]);
 }
 
 /**
@@ -104,6 +108,7 @@ export function ConversationCard({
   actionsDisabled = false,
 }: ConversationCardProps) {
   const { formatMessage } = useIntl();
+  const getTimeAgo = useTimeAgo();
   const [copied, setCopied] = React.useState(false);
 
   const status = statusConfig[execution.status] || statusConfig.error;
@@ -180,7 +185,7 @@ export function ConversationCard({
               {execution.hasNativeSession && (
                 <Badge variant="outline" className="gap-1 text-xs">
                   <FileJson className="h-3 w-3" />
-                  native
+                  {formatMessage({ id: 'history.badge.native' })}
                 </Badge>
               )}
               <Badge variant={status.variant} className="gap-1 text-xs ml-auto">

ccw/frontend/src/components/shared/NativeSessionPanel.tsx

@@ -145,6 +145,7 @@ function TokenDisplay({ tokens, className }: TokenDisplayProps) {
  * ToolCallItem - Single tool call display with collapsible details
  */
 function ToolCallItem({ toolCall, index }: ToolCallItemProps) {
+  const { formatMessage } = useIntl();
   return (
     <details className="group/tool border border-border/50 rounded-md overflow-hidden">
       <summary className="flex items-center gap-2 px-3 py-2 text-xs cursor-pointer hover:bg-muted/50 select-none">
@@ -155,7 +156,7 @@ function ToolCallItem({ toolCall, index }: ToolCallItemProps) {
       <div className="border-t border-border/50 divide-y divide-border/50">
         {toolCall.arguments && (
           <div className="p-3">
-            <p className="text-xs font-medium text-muted-foreground mb-1">Input</p>
+            <p className="text-xs font-medium text-muted-foreground mb-1">{formatMessage({ id: 'nativeSession.toolCall.input' })}</p>
             <pre className="p-2 bg-muted/30 rounded text-xs whitespace-pre-wrap overflow-x-auto font-mono leading-relaxed max-h-60 overflow-y-auto">
               {toolCall.arguments}
             </pre>
@@ -163,7 +164,7 @@ function ToolCallItem({ toolCall, index }: ToolCallItemProps) {
         )}
         {toolCall.output && (
           <div className="p-3">
-            <p className="text-xs font-medium text-muted-foreground mb-1">Output</p>
+            <p className="text-xs font-medium text-muted-foreground mb-1">{formatMessage({ id: 'nativeSession.toolCall.output' })}</p>
             <pre className="p-2 bg-muted/30 rounded text-xs whitespace-pre-wrap overflow-x-auto font-mono leading-relaxed max-h-60 overflow-y-auto">
               {toolCall.output}
             </pre>

ccw/frontend/src/locales/en/history.json

@@ -1,6 +1,10 @@
 {
   "title": "CLI Execution History",
   "description": "View and manage your CLI execution history",
+  "tabs": {
+    "executions": "Executions",
+    "observability": "Session Audit"
+  },
   "searchPlaceholder": "Search executions...",
   "filterAllTools": "All Tools",
   "deleteOptions": "Delete Options",
@@ -9,10 +13,14 @@
   "deleteAll": "Delete All History",
   "actions": {
     "view": "View Details",
+    "viewNative": "View Native Session",
     "delete": "Delete",
     "copyId": "Copy ID",
     "copied": "Copied!"
   },
+  "badge": {
+    "native": "native"
+  },
   "dialog": {
     "deleteTitle": "Confirm Delete",
     "deleteAllTitle": "Delete All History",

ccw/frontend/src/locales/en/index.ts

@@ -41,6 +41,7 @@ import cliViewer from './cli-viewer.json';
 import team from './team.json';
 import terminalDashboard from './terminal-dashboard.json';
 import skillHub from './skill-hub.json';
+import nativeSession from './native-session.json';
 
 /**
  * Flattens nested JSON object to dot-separated keys
@@ -105,4 +106,5 @@ export default {
   ...flattenMessages(team, 'team'),
   ...flattenMessages(terminalDashboard, 'terminalDashboard'),
   ...flattenMessages(skillHub, 'skillHub'),
+  ...flattenMessages(nativeSession, 'nativeSession'),
 } as Record<string, string>;

ccw/frontend/src/locales/en/native-session.json

@@ -0,0 +1,33 @@
+{
+  "title": "Native Session",
+  "tokens": {
+    "total": "Total tokens",
+    "input": "Input tokens",
+    "output": "Output tokens",
+    "cached": "Cached tokens"
+  },
+  "turn": {
+    "latest": "Latest",
+    "thoughts": "Thoughts",
+    "toolCalls": "Tool Calls"
+  },
+  "toolCall": {
+    "input": "Input",
+    "output": "Output"
+  },
+  "meta": {
+    "startTime": "Start time",
+    "workingDir": "Working directory",
+    "projectHash": "Project hash",
+    "turns": "turns"
+  },
+  "tokenSummary": "Total Tokens",
+  "loading": "Loading session...",
+  "error": "Failed to load session",
+  "empty": "No session data available",
+  "footer": {
+    "copied": "Copied!",
+    "copySessionId": "Copy Session ID",
+    "exportJson": "Export JSON"
+  }
+}

ccw/frontend/src/locales/zh/history.json

@@ -1,6 +1,10 @@
 {
   "title": "CLI 执行历史",
   "description": "查看和管理 CLI 执行历史",
+  "tabs": {
+    "executions": "执行历史",
+    "observability": "会话审计"
+  },
   "searchPlaceholder": "搜索执行记录...",
   "filterAllTools": "全部工具",
   "deleteOptions": "删除选项",
@@ -9,10 +13,14 @@
   "deleteAll": "删除全部历史",
   "actions": {
     "view": "查看详情",
+    "viewNative": "查看原生会话",
     "delete": "删除",
     "copyId": "复制 ID",
     "copied": "已复制！"
   },
+  "badge": {
+    "native": "原生"
+  },
   "dialog": {
     "deleteTitle": "确认删除",
     "deleteAllTitle": "删除全部历史",

ccw/frontend/src/locales/zh/index.ts

@@ -41,6 +41,7 @@ import cliViewer from './cli-viewer.json';
 import team from './team.json';
 import terminalDashboard from './terminal-dashboard.json';
 import skillHub from './skill-hub.json';
+import nativeSession from './native-session.json';
 
 /**
  * Flattens nested JSON object to dot-separated keys
@@ -105,4 +106,5 @@ export default {
   ...flattenMessages(team, 'team'),
   ...flattenMessages(terminalDashboard, 'terminalDashboard'),
   ...flattenMessages(skillHub, 'skillHub'),
+  ...flattenMessages(nativeSession, 'nativeSession'),
 } as Record<string, string>;

ccw/frontend/src/locales/zh/native-session.json

@@ -0,0 +1,33 @@
+{
+  "title": "原生会话",
+  "tokens": {
+    "total": "总 Token 数",
+    "input": "输入 Token",
+    "output": "输出 Token",
+    "cached": "缓存 Token"
+  },
+  "turn": {
+    "latest": "最新",
+    "thoughts": "思考过程",
+    "toolCalls": "工具调用"
+  },
+  "toolCall": {
+    "input": "输入",
+    "output": "输出"
+  },
+  "meta": {
+    "startTime": "开始时间",
+    "workingDir": "工作目录",
+    "projectHash": "项目哈希",
+    "turns": "轮次"
+  },
+  "tokenSummary": "总 Token",
+  "loading": "加载会话中...",
+  "error": "加载会话失败",
+  "empty": "无会话数据",
+  "footer": {
+    "copied": "已复制！",
+    "copySessionId": "复制会话 ID",
+    "exportJson": "导出 JSON"
+  }
+}