refactor(tools): modularize tool system with AgentTool + TypeBox + i18n

- Delete monolithic registry.ts (−1185 lines)
- Add tools/definitions/ with 12 individual tool files + index.ts,
  each using AgentTool interface and TypeBox schemas
- Add tools/utils/ with shared helpers (format.ts, schemas.ts, time-params.ts)
- Rewrite tools/index.ts to provide getAllTools() factory
- Clean up tools/types.ts, keep only ToolContext and OwnerInfo
- Use i18n keys for tool descriptions, preserve Chinese as comments

electron/main/ai/tools/definitions/get-conversation-between.ts

@@ -0,0 +1,63 @@
+import { Type } from '@mariozechner/pi-ai'
+import type { AgentTool } from '@mariozechner/pi-agent-core'
+import type { ToolContext } from '../types'
+import { timeParamProperties } from '../utils/schemas'
+import * as workerManager from '../../../worker/workerManager'
+import { parseExtendedTimeParams } from '../utils/time-params'
+import { formatTimeRange, formatMessageCompact, t } from '../utils/format'
+
+const schema = Type.Object({
+  member_id_1: Type.Number({ description: 'ai.tools.get_conversation_between.params.member_id_1' }),
+  member_id_2: Type.Number({ description: 'ai.tools.get_conversation_between.params.member_id_2' }),
+  limit: Type.Optional(Type.Number({ description: 'ai.tools.get_conversation_between.params.limit' })),
+  ...timeParamProperties,
+})
+
+/** 获取两个群成员之间的对话记录。适用于回答"A和B之间聊了什么"、"查看两人的对话"等问题。需要先通过 get_group_members 获取成员 ID。支持精确到分钟级别的时间查询。 */
+export function createTool(context: ToolContext): AgentTool<typeof schema> {
+  return {
+    name: 'get_conversation_between',
+    label: 'get_conversation_between',
+    description: 'ai.tools.get_conversation_between.desc',
+    parameters: schema,
+    execute: async (_toolCallId, params) => {
+      const { sessionId, timeFilter: contextTimeFilter, maxMessagesLimit, locale } = context
+      const limit = maxMessagesLimit || params.limit || 100
+      const effectiveTimeFilter = parseExtendedTimeParams(params, contextTimeFilter)
+
+      const result = await workerManager.getConversationBetween(
+        sessionId,
+        params.member_id_1,
+        params.member_id_2,
+        effectiveTimeFilter,
+        limit
+      )
+
+      if (result.messages.length === 0) {
+        const data = {
+          error: t('noConversation', locale) as string,
+          member1Id: params.member_id_1,
+          member2Id: params.member_id_2,
+        }
+        return {
+          content: [{ type: 'text', text: JSON.stringify(data) }],
+          details: data,
+        }
+      }
+
+      const data = {
+        total: result.total,
+        returned: result.messages.length,
+        member1: result.member1Name,
+        member2: result.member2Name,
+        timeRange: formatTimeRange(effectiveTimeFilter, locale),
+        conversation: result.messages.map((m) => formatMessageCompact(m, locale)),
+      }
+
+      return {
+        content: [{ type: 'text', text: JSON.stringify(data) }],
+        details: data,
+      }
+    },
+  }
+}