Rename split-loop-with-lambda to slice-with-lambda

The refactoring is now published as Slice on sammancoaching.org:
https://sammancoaching.org/refactorings/slice.html

- git mv ideas/split-loop-with-lambda -> ideas/slice-with-lambda
- rename learning-hour file and update frontmatter name
- update paths in tools/rehearse scripts and report title
- update prose: 'Split Loop with Lambda' -> 'Slice with Lambda'
  in learning hour, exercise READMEs, storyboard, solution comments
- link the published Slice refactoring from the pattern draft

ideas/slice-with-lambda/exercise/rehearsal-runs/README.md

@@ -0,0 +1,32 @@
+# rehearsal-runs/ — curated per-run evidence (2026-09-27)
+
+One directory per sub-agent run. Generated by `tools/rehearse/run-rehearsal.sh`;
+full raw sessions (pi jsonl transcripts, complete workspaces) live in
+`/tmp/rehearsal/runs/<run>/` and are intentionally not committed.
+
+Per run:
+
+| File | Content |
+|------|---------|
+| `agents-md.txt` | The exact AGENTS.md the agent worked against (shared design instructions + variant tool rules) |
+| `prompt.txt` | The user prompt given to `pi -p` |
+| `measure.txt` | Tokens (sum + per-usage breakdown), turn/tool-call counts, session span, wall clock, tool-name histogram (from `measure_run.sh`) |
+| `verify.txt` | Deterministic gate result: diff size vs pristine, `mvn test` with the solution's test + approved file, structural checks (see `verify_outcome.sh`) |
+| `diff.patch` | Final diff of the run workspace vs the pristine exercise (excludes test artifacts) |
+| `pi-stdout.txt` | The agent's final report (summary + final diff as it saw it) |
+| `time.txt` | `/usr/bin/time -v` output (wall clock, max RSS, exit status) |
+| `mvn-verify-tail.log` | Tail of the mvn output for the gate run — only present for failures |
+
+Run → variant/model map:
+
+| Dir | Variant | Model |
+|-----|---------|-------|
+| `A`   | CLI mandated        | openrouter z-ai/glm-5.3-flash |
+| `B`   | plain pi tools      | openrouter z-ai/glm-5.3-flash |
+| `C`   | CLI optional + intro| openrouter z-ai/glm-5.3-flash |
+| `A+Q` | CLI mandated        | entrim Qwen/Qwen3.6-35B-A3B |
+| `B+Q` | plain pi tools      | entrim Qwen/Qwen3.6-35B-A3B |
+| `C+Q` | CLI optional + intro| entrim Qwen/Qwen3.6-35B-A3B |
+
+Narrative, drift documentation, and conclusions: see
+[`../rehearsal-findings.md`](../rehearsal-findings.md).