Split the Windows script into modules; drop the Arkylx Index pieces

claude-mode.ps1 was 2,407 lines. It is now 153: the help block, parameters,
paths, the managed-key list, a loader, and the dispatch. The rest moved,
verbatim, into eleven files under lib/ - providers, output, files, core,
vault, switch, guards, health, catalogue, commands, menu - dot-sourced into
the script's scope in their original order, with the same check as the bash
split that every original line landed in exactly one file. Inside a module
$PSScriptRoot is lib\, so the one path beside the main script
(providers.json) now goes through $script:Here.

install.ps1 ships lib\, clearing old modules first. The Windows suite
parses every module and install.ps1 (36 checks, all green on Windows
PowerShell 5.1); install.ps1 is parsed but never run, since it edits the
real profile and User PATH.

linux/bootstrap.sh and scripts/build-package.ps1 existed only to build and
serve packages for the Arkylx Index. Both installers fetch the repository's
own archive, so a push to master is the release; the two scripts, the dist/
ignore and their mentions in the docs are gone.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/windows/run-remote.sh

@@ -13,10 +13,11 @@ ssh_() { ssh -o BatchMode=yes -o LogLevel=ERROR -o ConnectTimeout=10 "$host" "$@
 parent="$(mktemp -d)"
 trap 'rm -rf "$parent"' EXIT
 stage="$parent/$name"
-mkdir -p "$stage/presets" "$stage/bin"
-cp claude-mode.ps1 providers.json VERSION tests/fake_server.py tests/windows/run.ps1 "$stage/"
+mkdir -p "$stage/presets" "$stage/bin" "$stage/lib"
+cp claude-mode.ps1 install.ps1 providers.json VERSION tests/fake_server.py tests/windows/run.ps1 "$stage/"
 cp presets/*.json "$stage/presets/"
 cp bin/* "$stage/bin/"
+cp lib/*.ps1 "$stage/lib/"
 
 rtemp="$(ssh_ 'Write-Output $env:TEMP' | tr -d '\r')" || { echo "cannot reach $host" >&2; exit 1; }
 [ -n "$rtemp" ] || { echo "no %TEMP% on $host" >&2; exit 1; }