Runs that go in circles end (M7.8)

Driver.run checks each turn with nisse_core.loop.circles and ends the run
as "circling" when the same calls get much the same back, one harness
correction is given again and again, or the model apologises, for
circle_repeats turns in a row (default 3). Near-identical calls (git add
a.py, b.py) and scattered apologies stay flags on the status page. A
fact in the transcript says why the run ended.

nisse-dev calls in a helper as for a stuck run, then asks the operator;
nisse-review counts a failed run and posts none of its drafts. Tuning:
tuning.driver / tuning.review circle_repeats (0 off) and circle_similar.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-dev/src/nisse_dev/config.py

@@ -25,6 +25,7 @@ from nisse_core.config import (
     REFERENCE,
     ConfigError,
     VaultConfig,
+    check_circles,
     flatten,
     llm_numbers,
     parse_tuning,
@@ -107,6 +108,10 @@ GENERAL = "general"  # the scope of conversation not about a project (L1)
 class DriverTuning:
     max_turns: int = 40
     failure_limit: int = 2
+    # A run going in circles ends (L2): this many alike turns in a row, or
+    # one correction given this often; 0 never ends one. And how alike.
+    circle_repeats: int = field(default=3, metadata={"zero": True})
+    circle_similar: float = 0.9
 
 
 @dataclass(frozen=True)
@@ -199,6 +204,12 @@ def _parse_tuning(raw: Any, errors: list[str]) -> Tuning:
     if tuning.context.safety_margin >= 1:
         errors.append("tuning.context.safety_margin: must be less than 1")
     check_tuning(tuning.context.compaction(), "tuning.context", errors)
+    check_circles(
+        tuning.driver.circle_repeats,
+        tuning.driver.circle_similar,
+        "tuning.driver",
+        errors,
+    )
     return tuning