feat(ai): 步数触顶改为 incomplete 可续跑

MAX_AGENT_STEPS 触顶保留已完成 steps，支持追问续跑；
补充 docs 与 zh/en 文案 maxStepsIncomplete。

src/i18n/locales/en/ai.json

@@ -81,7 +81,8 @@
     "execUnknown": "Unknown error",
     "execNoOutput": "Command finished with no output",
     "maxSteps": "Reached {{max}}-step limit; narrow the scope and retry",
-    "noOutput": "No terminal output to summarize"
+    "noOutput": "No terminal output to summarize",
+    "maxStepsIncomplete": "Incomplete (max_steps): hit the {{max}}-step budget. Narrow the task or follow up to resume with prior steps."
   },
   "output": {
     "empty": "(empty output)",

src/i18n/locales/en/errors.json

@@ -165,7 +165,8 @@
     "criticalBlocked": "Command hit a destructive hard block; no override: {{command}}",
     "execFailed": "Remote execution failed: {{error}}",
     "maxSteps": "Reached {{max}}-step limit; narrow the scope and retry",
-    "sshRequired": "A connected remote SSH session is required"
+    "sshRequired": "A connected remote SSH session is required",
+    "maxStepsIncomplete": "Incomplete (max_steps): hit the {{max}}-step budget. Narrow scope or follow up to resume."
   },
   "zmodem": {
     "readFailed": "Read failed: {{name}}",

src/i18n/locales/zh-CN/ai.json

@@ -81,7 +81,8 @@
     "execUnknown": "未知错误",
     "execNoOutput": "命令执行完成，无输出",
     "maxSteps": "已达 {{max}} 步上限，请缩小范围后重试",
-    "noOutput": "终端没有可总结的输出"
+    "noOutput": "终端没有可总结的输出",
+    "maxStepsIncomplete": "未完成（incomplete:max_steps）：已达 {{max}} 步预算。可缩小范围、或直接追问继续（会带着已有步骤续跑）。"
   },
   "output": {
     "empty": "（空输出）",

src/i18n/locales/zh-CN/errors.json

@@ -165,7 +165,8 @@
     "criticalBlocked": "命令命中破坏性操作硬红线，不提供确认放行：{{command}}",
     "execFailed": "远程执行失败：{{error}}",
     "maxSteps": "已达 {{max}} 步上限，请缩小范围后重试",
-    "sshRequired": "需要已连接的远程 SSH"
+    "sshRequired": "需要已连接的远程 SSH",
+    "maxStepsIncomplete": "未完成（incomplete:max_steps）：已达 {{max}} 步预算。可缩小范围或追问续跑。"
   },
   "zmodem": {
     "readFailed": "读取失败: {{name}}",