runtime Tcl Executables are installed here under the appropriate os_architecture folder.
e.g
  windows 64bit binaries under win32-x86_64
  windows 32bit binaries under win32-ix86
  linux 64 bit binaries under linux-x86_64

## What belongs in a platform folder

A platform folder is a store TIER: it holds runtime executables FOR that platform. The
folder need not match the machine you are on - a tier for another platform is a
first-class thing to populate, because the kit build reads each kit's tier from that
kit's target platform rather than from the driving tclsh (see src/AGENTS.md).

Everything in the folder that is not recognised as a support file is treated as a
selectable runtime by `bin/punk-runtime.cmd list` and `use`. Support files are
recognised by extension and are tolerated beside the runtimes without appearing as
candidates:

  docs/text     .txt .md .html .htm .pdf .url
  config/meta   .toml .json .xml .yml .yaml .ini .cfg
  dev leftovers .tm .tmp .log .bak .old
  checksums     .sha1 .sha256 .asc .sig
  archives      .zip .tar .gz .bz2 .xz .7z

plus any name containing `_BUILDCOPY`. That covers what legitimately accumulates here:
`active.toml` (which runtime `run` launches - per-machine, not versioned), a runtime's
`<rootname>.toml` artifact-metadata record, a cached `sha1sums.txt`, a downloaded
checksum or signature, notes about where a runtime came from, and a build-request file
such as the `.cfg` a Lean Undroidwish Construction Kit build is reproducible from.

Anything else - including a stray binary that is not a Tcl runtime - WILL be offered as
a runtime, so keep unrelated executables out of these folders. If a new kind of support
file starts appearing here regularly, extend the recognised set in BOTH payloads
(`src/scriptapps/bin/punk-runtime.ps1` and `.bash` - see the shared
`PunkRuntimeSupportExt` / `is_punk_support_name` definitions) and re-wrap; the two
listings are required to agree byte-for-byte.

The folders themselves are not versioned (the `bin/*` ignore globs cover them), so
nothing here is a place to keep anything you cannot re-fetch or rebuild.

The bin/punk-runtime.cmd cross-platform script can be used to download prebuilt Tcl binaries.
e.g ./bin/punk-runtime.cmd fetch
This will detect the platform and architecture, creating the containing folder as necessary.

To see existing installed runtimes:
 ./bin/punk-runtime.cmd list
Or to compare local runtimes with those available on the artifact server:
 ./bin/punk-runtime.cmd list -remote

 An installed runtime can then be used to call the src/make.tcl file.

e.g - initial check
  ./bin/punk-runtime.cmd run src/make.tcl check

e.g - to build (or just copy with latest version number from src if build not required) modules to projectdir/modules 
  ./bin/punk-runtime.cmd run src/make.tcl modules
 for libs & modules
  ./bin/punk-runtime.cmd run src/make.tcl packages