Extract one Resolve-ToolPath helper for Windows binary lookup #96

Context

Roughly 11 Windows PowerShell chezmoiscripts each carry their own copy of "find this tool's binary" logic — a Resolve-*Path function or an inline candidate-paths array plus a Get-Command fallback. That's ~350 lines of near-identical lookup logic. Each script is shallow at the lookup seam: the same fallback search is duplicated everywhere with only the tool name and candidate paths varying.

A smaller, related duplication: Assert-LastExitCode is defined identically in at least run_after_90_package_updates_windows.ps1.tmpl and run_onchange_after_bootstrap_windows.ps1.tmpl.

Files

Scripts with bespoke tool resolution (non-exhaustive):

• home/.chezmoiscripts/run_onchange_after_glazewm_reload_windows.ps1.tmpl (Resolve-GlazeExePath)
• home/.chezmoiscripts/run_onchange_after_komorebi_reload_windows.ps1.tmpl (Resolve-KomorebicPath)
• home/.chezmoiscripts/run_onchange_after_pi_packages_windows.ps1.tmpl (Get-PiCommand)
• home/.chezmoiscripts/run_onchange_after_mise_install_windows.ps1.tmpl (inline $miseCandidates)
• home/.chezmoiscripts/run_after_90_package_updates_windows.ps1.tmpl
• home/.chezmoiscripts/run_onchange_after_bootstrap_windows.ps1.tmpl
• home/.chezmoiscripts/run_onchange_after_choco_review_windows.ps1.tmpl ($bashCandidates)
• plus several more with inline variants

Shared template to extend:

• home/.chezmoitemplates/windows-elevation.ps1.tmpl

What to do

1. Add home/.chezmoitemplates/windows-resolve-tool-path.ps1.tmpl: a parameterised helper that takes a tool name + candidate path list and returns a resolved path (Get-Command → candidate paths → fail), included the same way windows-elevation.ps1.tmpl is.
2. Replace each bespoke Resolve-* function / inline array with a call to the shared helper.
3. Move Assert-LastExitCode into windows-elevation.ps1.tmpl so callers inherit it instead of redefining it.
4. Confirm every touched .ps1.tmpl still renders to empty on non-Windows ({{ if eq .chezmoi.os "windows" }} guards intact).

Out of scope

• Changing what any script does once it has the binary path.
• Non-Windows scripts.