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>

lib/providers.ps1

@@ -0,0 +1,60 @@
+# lib/providers.ps1 - every gateway provider, read from providers.json, and lookups into them.
+#
+# Part of claude-mode.ps1, which dot-sources it into its own script scope after
+# the settings at its top. Not meant to run on its own. ASCII only: Windows
+# PowerShell 5.1 reads a .ps1 without a BOM as ANSI. $PSScriptRoot here would be
+# lib\, so paths beside the main script go through $script:Here.
+
+# ---------------------------------------------------------------------------
+# Providers
+#
+# Every gateway provider is an entry in providers.json, next to this script and
+# shared with the POSIX build: endpoint, auth, how its model list is fetched,
+# which doctor checks apply. This script only knows the *kinds* of behaviour
+# (Get-ProviderCatalogue, Test-PresetCatalogue) and picks one by name from the
+# entry, so a provider that reuses them needs no change here. anthropic is
+# built in: it is the native login, not a gateway.
+# ---------------------------------------------------------------------------
+
+$script:ProvidersPath = Join-Path $script:Here 'providers.json'
+$script:Providers = @()
+try {
+    $__pj = Get-Content -LiteralPath $script:ProvidersPath -Raw -Encoding UTF8 | ConvertFrom-Json
+    $script:Providers = @($__pj.providers | Where-Object { $_.id })
+} catch { }
+if ($script:Providers.Count -eq 0) {
+    Write-Host "  FAIL providers.json missing or unreadable at $($script:ProvidersPath) - re-run install.ps1" -ForegroundColor Red
+    exit 1
+}
+
+$script:Modes     = @('anthropic') + @($script:Providers | ForEach-Object { [string]$_.id })
+$script:ModeLabel = @{ 'anthropic' = 'Anthropic  - your subscription login, no gateway' }
+
+# `claude-mode <provider>` with no preset named uses this one. Deliberately a
+# fixed choice rather than "most recently used", so the command is predictable.
+$script:ProviderDefaultPreset = @{}
+foreach ($__p in $script:Providers) {
+    $script:ModeLabel[[string]$__p.id] = [string]$__p.label
+    $script:ProviderDefaultPreset[[string]$__p.id] = $(if ($__p.defaultPreset) { [string]$__p.defaultPreset } else { [string]$__p.id })
+}
+
+function Get-Provider {
+    param([string] $Id)
+    return ($script:Providers | Where-Object { $_.id -eq $Id } | Select-Object -First 1)
+}
+
+# An id or an alias (z.ai, z-ai) to the provider id; $null if neither.
+function Resolve-ProviderId {
+    param([string] $Word)
+    $w = ([string]$Word).ToLower()
+    foreach ($p in $script:Providers) {
+        if ([string]$p.id -eq $w -or (@($p.aliases) -contains $w)) { return [string]$p.id }
+    }
+    return $null
+}
+
+function Test-ProviderDoctor {
+    param([string] $Id, [string] $Check)
+    $p = Get-Provider $Id
+    return [bool]($p -and (@($p.doctor) -contains $Check))
+}