fix(hooks): rewrite install_hook_wrapper.ps1 to avoid argv-dup bug

Under Claude Code v2.1.116 the first argv token of a hook command is
duplicated. When the token is a quoted Windows .exe path, bash.exe is
re-invoked with itself as script (exit 126). PR #1524 fixed the shape
of settings.local.json; this script keeps the installer consistent so
re-running it does not regenerate the broken form.

Changes:
- First token is now PATH-resolved `bash` instead of the quoted bash.exe
- Wrapper path is normalized to forward slashes for MSYS safety
- PreToolUse and PostToolUse get distinct pre/post positional arguments
- JSON output is written with LF endings (no mixed CRLF/LF)

Companion doc: docs/fixes/INSTALL-HOOK-WRAPPER-FIX-20260422.md

docs/fixes/install_hook_wrapper.ps1

@@ -0,0 +1,73 @@
+# Install observe-wrapper.sh + rewrite settings.local.json to use it
+# No Japanese literals - uses $PSScriptRoot instead
+# argv-dup bug workaround: use `bash` (PATH-resolved) as first token and
+# normalize wrapper path to forward slashes. See PR #1524.
+$ErrorActionPreference = "Stop"
+
+$SkillHooks   = "$env:USERPROFILE\.claude\skills\continuous-learning\hooks"
+$WrapperSrc   = Join-Path $PSScriptRoot "observe-wrapper.sh"
+$WrapperDst   = "$SkillHooks\observe-wrapper.sh"
+$SettingsPath = "$env:USERPROFILE\.claude\settings.local.json"
+# Use PATH-resolved `bash` to avoid Claude Code v2.1.116 argv-dup bug that
+# double-passes the first token when the quoted path is a Windows .exe.
+$BashExe      = "bash"
+
+Write-Host "=== Install Hook Wrapper ===" -ForegroundColor Cyan
+Write-Host "ScriptRoot: $PSScriptRoot"
+Write-Host "WrapperSrc: $WrapperSrc"
+
+if (-not (Test-Path $WrapperSrc)) {
+    Write-Host "[ERROR] Source not found: $WrapperSrc" -ForegroundColor Red
+    exit 1
+}
+
+# 1) Copy wrapper + LF normalization
+Write-Host "[1/4] Copy wrapper to $WrapperDst" -ForegroundColor Yellow
+$content = Get-Content -Raw -Path $WrapperSrc
+$contentLf = $content -replace "`r`n","`n"
+$utf8 = [System.Text.UTF8Encoding]::new($false)
+[System.IO.File]::WriteAllText($WrapperDst, $contentLf, $utf8)
+Write-Host "  [OK] wrapper installed with LF endings" -ForegroundColor Green
+
+# 2) Backup settings
+Write-Host "[2/4] Backup settings.local.json" -ForegroundColor Yellow
+$backup = "$SettingsPath.bak-$(Get-Date -Format 'yyyyMMdd-HHmmss')"
+Copy-Item $SettingsPath $backup -Force
+Write-Host "  [OK] $backup" -ForegroundColor Green
+
+# 3) Rewrite command path in settings.local.json
+Write-Host "[3/4] Rewrite hook command to wrapper" -ForegroundColor Yellow
+$settings = Get-Content -Raw -Path $SettingsPath -Encoding UTF8 | ConvertFrom-Json -AsHashtable
+
+# Normalize wrapper path to forward slashes so bash (MSYS/Git Bash) does not
+# mangle backslashes; quoting keeps spaces safe.
+$wrapperPath = $WrapperDst -replace '\\','/'
+$preCmd  = $BashExe + ' "' + $wrapperPath + '" pre'
+$postCmd = $BashExe + ' "' + $wrapperPath + '" post'
+
+foreach ($entry in $settings.hooks.PreToolUse) {
+    foreach ($h in $entry.hooks) {
+        $h.command = $preCmd
+    }
+}
+foreach ($entry in $settings.hooks.PostToolUse) {
+    foreach ($h in $entry.hooks) {
+        $h.command = $postCmd
+    }
+}
+
+$json = $settings | ConvertTo-Json -Depth 20
+# Normalize CRLF -> LF so hook parsers never see mixed line endings.
+$jsonLf = $json -replace "`r`n","`n"
+[System.IO.File]::WriteAllText($SettingsPath, $jsonLf, $utf8)
+Write-Host "  [OK] command updated" -ForegroundColor Green
+Write-Host "  PreToolUse  command: $preCmd"
+Write-Host "  PostToolUse command: $postCmd"
+
+# 4) Verify
+Write-Host "[4/4] Verify" -ForegroundColor Yellow
+Get-Content $SettingsPath | Select-String "command"
+
+Write-Host ""
+Write-Host "=== DONE ===" -ForegroundColor Green
+Write-Host "Next: Launch Claude CLI and run any command to trigger observations.jsonl"