feat(ltm): pre-fill default LTM summary prompt in config and i18n

Author: RC-CHN

astrbot/core/config/default.py

@@ -227,7 +227,15 @@
         "ltm_summary_trigger_rounds": 80,
         "ltm_summary_keep_recent_rounds": 30,
         "ltm_summary_provider_id": "",
-        "ltm_summary_prompt": "",
+        "ltm_summary_prompt": (
+            "Merge the older conversation rounds below into the existing "
+            "group-chat memory summary. "
+            "Preserve: user identities (names, nicknames, roles), recurring topics, "
+            "decisions made, preferences expressed, and unresolved tasks or questions. "
+            "Drop: transient greetings, small talk, and redundant confirmations. "
+            "Keep the summary concise and factual. "
+            "Output only the updated summary text, with no preamble or meta-commentary."
+        ),
         "ltm_raw_records_max_bytes": 500000,
         # When building user segments, both limits are active simultaneously:
         # whichever cap is hit first (by count or by chars) stops accumulation.
@@ -4195,7 +4203,7 @@
                     "provider_ltm_settings.ltm_summary_prompt": {
                         "description": "LTM 摘要提示词",
                         "type": "string",
-                        "hint": "llm_summary 策略的自定义摘要 prompt，留空使用内置默认。",
+                        "hint": "llm_summary 策略的自定义摘要 prompt，不更改以使用内置默认。",
                         "condition": {
                             "provider_ltm_settings.ltm_compaction_strategy": "llm_summary",
                         },

dashboard/src/i18n/locales/en-US/features/config-metadata.json

@@ -1027,7 +1027,7 @@
         },
         "ltm_summary_prompt": {
           "description": "LTM Summary Prompt",
-          "hint": "Custom summary prompt for llm_summary strategy. Leave empty for built-in default."
+          "hint": "Custom summary prompt for llm_summary strategy. Keep unchanged to use the built-in default."
         },
         "ltm_raw_records_max_bytes": {
           "description": "Raw Message Buffer Memory Limit",

dashboard/src/i18n/locales/ru-RU/features/config-metadata.json

@@ -1028,7 +1028,7 @@
                 },
                 "ltm_summary_prompt": {
                     "description": "Промпт для LTM резюме",
-                    "hint": "Свой промпт для llm_summary. Оставьте пустым для встроенного по умолчанию."
+                    "hint": "Свой промпт для llm_summary. Не изменяйте, чтобы использовать встроенный по умолчанию."
                 },
                 "ltm_raw_records_max_bytes": {
                     "description": "Лимит буфера сообщений",

dashboard/src/i18n/locales/zh-CN/features/config-metadata.json

@@ -1029,7 +1029,7 @@
         },
         "ltm_summary_prompt": {
           "description": "LTM 摘要提示词",
-          "hint": "llm_summary 策略的自定义摘要 prompt，留空使用内置默认。"
+          "hint": "llm_summary 策略的自定义摘要 prompt，不更改以使用内置默认。"
         },
         "ltm_raw_records_max_bytes": {
           "description": "原始消息缓冲区内存上限",