revert: hold round-3 nano changes for review (PR 20)

eval/harbor/run_tb21_nano_max.sh

@@ -83,7 +83,6 @@ PYTHONPATH="$ROOT/eval/harbor" harbor run \
   --ak "source=$WHEEL" \
   --ak nano=1 \
   --ak effort=max \
-  --ak "max_turns=${NANO_MAX_TURNS:-600}" \
   ${AK_EXTRA[@]+"${AK_EXTRA[@]}"}
 
 echo

src/nano/prompt.py

@@ -76,13 +76,9 @@
     "files merely by opening them",
     "- Get a minimal working version of the requested deliverable in "
     "place early, then iterate to improve it",
-    "- Run long builds, training runs, or downloads as ONE blocking bash "
-    "command (tee output to a log) — never launch with nohup and poll in "
-    "a loop",
-    "- Before finishing, re-read the task and list every explicit "
-    "requirement and constraint (exact formats, tolerances, numeric "
-    "bounds, required sources or methods), then test your artifact "
-    "against each one; plausible output is not verified output",
+    "- Before finishing, re-read the task and verify each explicit "
+    "requirement against what you actually produced; plausible output "
+    "is not verified output",
     "- Be concise in your responses",
     "- Show file paths clearly when working with files",
 )

src/nano/tool_docs.py

@@ -22,11 +22,8 @@
     ),
     "Bash": (
         "Executes a bash command and returns stdout+stderr. The working "
-        "directory persists between commands; shell state does not. No "
-        "default timeout: a long build or training run can block in a "
-        "single call (tee output to a log file) — pass timeout (ms) only "
-        "when you want one. Long output is truncated. Quote paths "
-        "containing spaces."
+        "directory persists between commands; shell state does not. Long "
+        "output is truncated. Quote paths containing spaces."
     ),
     # Edit is intentionally absent: the nano registry swaps in
     # NanoEditTool (src/nano/edit_tool.py), which carries its own doc for

src/tool_system/tools/bash/bash_tool.py

@@ -659,37 +659,19 @@ def _bash_call(tool_input: dict[str, Any], context: ToolContext) -> ToolResult:
         )
 
     # Resolve timeout: prefer explicit timeout (ms), fall back to timeout_s (legacy), then default
-    #
-    # Nano mode removes the ceiling entirely (pi's bash has no default
-    # timeout). Measured on TB 2.1 (tb21-nano-flash-max-2): the 2-minute
-    # default / 10-minute cap forced nohup-and-poll loops on every long
-    # build or training run — 225 poll-pattern commands across the 25
-    # failed tasks, with compile-compcert alone burning 111 polls and
-    # dying at the 300-turn ceiling mid-build. One blocking call costs
-    # zero turns; the benchmark/task wall-clock and the abort signal
-    # (checked continuously by _run_supervised) remain the backstops.
-    from src.nano.state import is_nano_mode as _bash_is_nano
-
-    _nano = _bash_is_nano()
-    _NANO_NO_TIMEOUT_S = 86_400  # 24h — effectively "until abort/wall-clock"
     timeout_ms = tool_input.get("timeout")
     if timeout_ms is not None:
         max_ms = get_max_timeout_ms()
         if not isinstance(timeout_ms, (int, float)) or timeout_ms < 1000:
             raise ToolInputError("timeout must be at least 1000 ms")
-        if timeout_ms > max_ms and not _nano:
+        if timeout_ms > max_ms:
             raise ToolInputError(f"timeout must not exceed {max_ms} ms")
         timeout_s = int(timeout_ms / 1000)
     else:
         timeout_s = tool_input.get("timeout_s")
         if timeout_s is None:
-            timeout_s = (
-                _NANO_NO_TIMEOUT_S if _nano
-                else int(get_default_timeout_ms() / 1000)
-            )
-        if not isinstance(timeout_s, int) or timeout_s < 1 or (
-            timeout_s > 600 and not _nano
-        ):
+            timeout_s = int(get_default_timeout_ms() / 1000)
+        if not isinstance(timeout_s, int) or timeout_s < 1 or timeout_s > 600:
             raise ToolInputError("timeout_s must be an integer between 1 and 600")
 
     # Persist cwd across invocations (port of ``typescript/src/utils/Shell.ts``,