rebase: raise the module agent turn budget to 400

doc/architecture/SPEC/rebase_engine.md

@@ -137,3 +137,10 @@ choke-point 编号（agent_loop/rebase_tools 写"C5"）落后于 `_CONSTRAINTS.m
 
 `module_rebase` 既可跑进程内 agent 循环，也可把一个 module 交给 harness
 provider；两条路径共用同一 prompt、同一工具面与同一 plan gate。
+
+## module agent 轮次预算（2026-09-19）
+
+`RebaseModuleConfig.max_turns` = 400。耗尽预算不致命：引擎会**重启** agent
+循环而不是判 module 失败——但重启会丢掉已积累的上下文，所以预算过低时
+agent 会反复从头探索。flash 级模型在同一 module 上约需 pro 级 2.3 倍轮次
+（140+ vs 62），150 的旧上限会被截断三次仍未完成。

src/infermatrix_copilot/rebase_engine/module_rebase.py

@@ -36,7 +36,14 @@ class ModuleRunConfig:
     last_rebase_vllm_commit: str = ""
     cuda_devices: str = "0,1"
     hf_home: str = "/model"
-    max_turns: int = 150
+    # Raised from 150 for the v0.30.0 campaign: a flash-class module agent
+    # needs ~2.3x the turns of the pro tier on the same module (140+ vs 62),
+    # mostly shell exploration before the first edit. Exhausting the budget
+    # is NOT fatal — the engine restarts the agent loop — but a restart
+    # discards accumulated context, so too low a ceiling makes the agent
+    # re-explore from scratch. Bounds the in-process loop; a harness session
+    # is bounded by `harness_timeout_s` instead (see below).
+    max_turns: int = 400
     # Harness backend selection (doc/features/provider-registry.md). "api"
     # keeps the in-process Anthropic tool-use loop; any other provider id
     # delegates the whole module step to that harness, with the SAME 20-tool