chore: add shared skills catalog (19 skills), installers, manifest, validator

install.ps1

@@ -0,0 +1,47 @@
+# dsh-skills — shared DeepSeek Harness skills installer (Windows / PowerShell)
+# Copies/updates the skills catalog into the DSH user skills directory.
+<#
+.SYNOPSIS
+  Installs or updates the shared dsh-skills catalog into $DSH_HOME\skills.
+
+.DESCRIPTION
+  Syncs this repository's skills/ directory into the DSH skills root so
+  dsh-skill-filesystem discovers them. Defaults the DSH skills dir from
+  $env:DSH_HOME, else ~/.dsh. Accepts an explicit target dir.
+
+.EXAMPLE
+  .\install.ps1
+  .\install.ps1 -Target C:\Users\me\.dsh\skills -Source clone
+#>
+[CmdletBinding()]
+param(
+  [string]$Target,
+  [string]$SourceRoot = (Split-Path -Parent $PSScriptRoot)
+)
+
+function Get-DshSkillsDir {
+  param([string]$t)
+  if ($t) { return $t }
+  $home = $env:DSH_HOME
+  if (-not $home) { $home = Join-Path $env:USERPROFILE ".dsh" }
+  return (Join-Path $home "skills")
+}
+
+$target = Get-DshSkillsDir -t $Target
+Write-Host "Skills target: $target"
+New-Item -ItemType Directory -Force -Path $target -ErrorAction SilentlyContinue | Out-Null
+
+$src = Join-Path $SourceRoot "skills"
+if (-not (Test-Path $src)) {
+  Write-Error "skills/ directory not found at $src. Run from a repo clone."
+  exit 1
+}
+
+# Copy each skill bundle; preserve nested resources/scripts.
+Get-ChildItem -Path $src -Directory | ForEach-Object {
+  $dest = Join-Path $target $_.Name
+  Write-Host "Syncing skill: $($_.Name)"
+  Copy-Item -Path $_.FullName -Destination $dest -Recurse -Force
+}
+
+Write-Host "Done. Skills installed to $target. Restart the agent to refresh the catalog."