docs(template): add BENCH-RULES.md for engine-building runs

Rules for the runs were being made up mid-run (git for rollback, access
to the real-part drawing archive), so each model started under a
different rule set. BENCH-RULES.md writes them down in one place, stamped
into every new engine, so all models work under the same rules:
workspace limits and no searching for other engines, git init plus
commit-per-working-state, the archive as read-only with nothing
customer-identifying kept in the (publishable) engine folder, tests may
only be added to, and what the final report must cover.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

_Template/BENCH-RULES.md

@@ -0,0 +1,60 @@
+# Bench rules
+
+These rules apply to every model building or optimizing an OpenNest engine, so results can be
+compared fairly. `README.md` in this folder covers what counts as an independent engine; this
+file covers how the run itself works.
+
+## Your workspace
+
+- You are working in a copy of OpenNest. Your engine is `Engines/OpenNest.Engine.__NAME__/`.
+- Work only inside this copy. Do not search the rest of the filesystem, other checkouts of
+  OpenNest, the network, or any git remote for other nesting engines or earlier versions of
+  this project. Using another engine's code or results in any form is disqualifying.
+- Do not edit `OpenNest.Core`, `OpenNest.Engine`, `OpenNest.Benchmark` or anything else outside
+  your engine folder, except for throwaway tools under `tools/` and scratch work under
+  `bench-local/` (see below). If shared code has a bug that blocks you, work around it in your
+  engine and describe the bug in your report.
+
+## Version control
+
+- At the start, if this copy is not already a git repository, run `git init` in the copy's root
+  and commit everything as `Initial bench copy` before changing anything.
+- Commit every time the engine reaches a working state (it builds and the tests pass), with a
+  message that says what changed and why, plus any benchmark numbers you measured.
+- When an experiment makes things worse, go back to the last good commit rather than
+  patching forward. Do not rewrite or squash history; the commit log is part of the record
+  of your run.
+- Do not add a git remote or push anywhere.
+
+## Real parts
+
+- Real production drawings are available read-only at `/mnt/rogers/PEP Drawings/Archive`.
+  Use them to build realistic benchmark jobs.
+- Never modify, move or delete anything in the archive.
+- Do not copy DXF files into your engine folder, and do not commit archive paths, file names or
+  part numbers inside your engine folder. The engine folder may be published; these drawings
+  are customer property. Keep manifests, results and notes that reference the archive under
+  `bench-local/` in the copy's root instead.
+- Final scoring also uses jobs you will not see. Tune for real parts in general, not for the
+  specific drawings you tested with.
+
+## Tests and scoring
+
+- Keep the starter tests in `tests/` and keep them passing. Add tests; do not weaken,
+  skip or delete existing ones. If you believe an existing test is wrong, leave it and explain
+  why in your report.
+- Engines are scored by `OpenNest.Benchmark`. Every layout goes through `NestValidator`; an
+  invalid layout places nothing and pays the unplaced-part penalty, so validity comes before
+  utilization.
+- Benchmark with `--parallel 1` whenever you report timing.
+
+## Your report
+
+When you finish, update `README.md` in your engine folder to replace the template text with:
+
+- the algorithm and why you chose it,
+- what you tried that did not work,
+- benchmark results (synthetic jobs only in the README; real-part results go in
+  `bench-local/`),
+- any shared-code bugs or improvements you found, with measured numbers, so they can be
+  upstreamed.

_Template/README.md

@@ -11,6 +11,9 @@ several of them and keep the best result.
 The decisions that make it an engine must be yours: which sheet(s) to use, which parts go
 where and in what order, which pattern/strategy to apply to which region, and when to stop.
 
+**Read `BENCH-RULES.md` before starting.** It covers your workspace, version control, the
+real-part drawing archive, tests and your final report.
+
 ## Allowed building blocks
 
 Reuse is encouraged. These are tools you drive, composed by your own decision logic: