# batches/ — convention only; the data lives under `user://`

This folder documents the batch layout. **It does not hold batches.**

Real batch output is written under `ISLA_OUTPUT_DIR` (default `user://output/batches`), resolved by
`Core/Scripts/ToolingPaths.cs`. Generated worlds are large, regenerable, and do not belong in git.

## Layout

```
batches/<chat>/NN_<name>/           <chat> = the chat namespace · NN = the task number that ran it
├── INDEX.md                        what varied, what to look at, what was concluded
├── scratch/                        intermediates — PERSISTENT, never cleaned
└── <seed>_<variant>/               one directory per generated world
```

### ⭐ The `<chat>` segment (rivers/01)

**`NN` is the AUTHORING TASK NUMBER, and task numbers restart at 00 in every build chat** — so a flat
`batches/` collides the moment a second chat exists. It did: chat 1's `02_pass1_port` and chat 2's
`02_curve_continuous` are both "batch 02", and nothing in either name says which chat made it. On the
real pile there were **four colliding prefixes (02, 03, 04, 06)** across 25 batches, separable only by
SLUG.

The slug is set by `ToolingPaths.ConfigureChat(...)` and is **required** — with none set, `BatchRoot`
throws rather than writing to the un-namespaced root. Each tool defaults to its own authoring chat, so
re-running it reproduces its batch in place; **`ISLA_CHAT` redirects a run to another namespace**, which
is what keeps an acceptance run from overwriting the very anchor it is checking against.

> ### ⚠ Writes are namespaced; historical READS carry the prefix themselves.
> `BatchRoot(task, descriptor)` inserts `<chat>`. `BatchesRoot` is the plain root, and every
> `ISLA_*_SOURCE` anchor composes against it — so an anchor default is written out in full, e.g.
> `"chat1/02_pass1_port"`. Namespacing only the writes would silently orphan every historical read.
> **That is why a missing anchor now THROWS** (`ShapingOracle.LoadAnchor`): a moved anchor used to make
> its oracle not RUN, and a batch with a silently-skipped check prints an all-PASS table that reads
> exactly like a clean one.

`INDEX.md` is not optional. A/B comparisons are browsed by a human, and a flat directory of
same-named PNGs is not browsable.

## ⚠ No deletions here. Ever.

`FileSafety.AssertDeletable` refuses any path under the batches root, and it refuses without a
stated reason regardless. **Intermediates persist.** Any deletion that does happen elsewhere is
named explicitly in the run report.

→ `Tools/README.md`, `Design - Tooling - Iteration and Batching.md`