Add agent rehearsal harness, findings, and per-run evidence for split-loop-with-lambda

Six scripted pi sub-agent runs (3 tool regimes × 2 models) rehearsed the
exercise; deterministic gate = solution test + approved file. Key results:
mandated CLI triples cost on the strong model (4:06 vs 0:39, PASS both);
weak model fails only under the mandate (A+Q), passes when free or optional.
Drift documented with code: scorer.updateSelection left inside the extracted
method (A+Q, C+Q). Harness in tools/rehearse; summary in
rehearsal-findings.md; per-run evidence in rehearsal-runs/; cheat sheet in
rehearse-with-agent.md corrected (lambda-typed parameters unsupported).

ideas/split-loop-with-lambda/exercise/rehearsal-runs/C+Q/measure.txt

@@ -0,0 +1,35 @@
+--- Run C+Q ---
+session file: /tmp/rehearsal/runs/C+Q/session/2026-09-27T15-53-02-700Z_01a0e391-ddec-76b3-83b6-8a55d163bf7c.jsonl
+model:                Qwen/Qwen3.6-35B-A3B
+session span:         71.7 s
+assistant messages:   16
+tool calls:           17 total
+  bash                     7
+  read                     5
+  edit                     5
+tokens input:         138747
+tokens output:        8337
+tokens cacheRead:     0
+tokens cacheWrite:    0
+tokens reasoning:     2579
+tokens TOTAL (sum):   149663
+--- /usr/bin/time -v (wall clock + max RSS) ---
+	Elapsed (wall clock) time (h:mm:ss or m:ss): 1:11.84
+	Maximum resident set size (kbytes): 226488
+	Exit status: 0
+--- pi stdout (last 15 lines) ---
++            long daysForward = ChronoUnit.DAYS.between(forecastDate, date);
++            expectedWeather.add(dayOffsetToWeather.apply(daysForward));
++        }
++        return expectedWeather;
++    }
+ }
+```
+
+## Summary of changes:
+
+| Step | Change |
+|------|--------|
+| **1** | Added `import java.util.function.LongFunction`; introduced `dayOffsetToWeather` lambda wrapping `scorer.lookupWeather()` in the original method body, replacing direct scorer calls |
+| **2** | Extracted the weather-collection loop into a new `private List<Boolean> collectExpectedWeather(List<Instant>, LongFunction<Boolean>)` method |
+| **3** | Removed `String quarter` parameter; added a **no-arg** `longRangeForecast()` that delegates to the parameterized overload wrapping the `scorer`; renamed the main method to accept `LongFunction<Boolean> dayOffsetToWeather` |