feat: bootstrap scripts auto-launch the installer

get-cameleer.sh and get-cameleer.ps1 now download the installer files
and exec install.sh / install.ps1 immediately instead of just printing
a "run this next" hint. Extra arguments are forwarded to the installer.

PowerShell bootstrap fetches install.ps1 (not install.sh) so Windows
users no longer need bash. README updated to use the bash -c "$(curl ...)"
form so install.sh's interactive prompts inherit the user's TTY.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

get-cameleer.ps1

@@ -4,12 +4,13 @@
   Bootstrap script — downloads the Cameleer installer and runs it.
 .EXAMPLE
   irm https://registry.cameleer.io/cameleer/cameleer-saas-installer/raw/branch/main/get-cameleer.ps1 | iex
-  .\get-cameleer.ps1 -Version v1.2.0
+  & ([scriptblock]::Create((irm https://.../get-cameleer.ps1))) -Version v1.2.0
 #>
 param(
     [string]$Version,
     [string]$Ref,
-    [switch]$Run
+    [Parameter(ValueFromRemainingArguments = $true)]
+    [string[]]$InstallerArgs
 )
 
 $ErrorActionPreference = 'Stop'
@@ -23,7 +24,7 @@ $Base = "$Repo/$RefPath"
 $Dir  = '.\installer'
 
 $Files = @(
-    'install.sh'
+    'install.ps1'
     'templates/docker-compose.yml'
     'templates/docker-compose.saas.yml'
     'templates/docker-compose.server.yml'
@@ -47,11 +48,13 @@ foreach ($file in $Files) {
 }
 
 Write-Host ''
-Write-Host "Installer ready in $Dir\"
-Write-Host 'Run:  cd installer; .\install.sh'
+Write-Host "Installer downloaded to $Dir\ — launching..."
 Write-Host ''
 
-if ($Run) {
-    Set-Location $Dir
-    & .\install.sh @args
+Set-Location $Dir
+if ($InstallerArgs) {
+    & .\install.ps1 @InstallerArgs
+} else {
+    & .\install.ps1
 }
+exit $LASTEXITCODE