feat: major dotfiles refactor with documentation and multi-platform improvements

- Add comprehensive CLAUDE.md with chezmoi best practices and AI assistant guidelines
- Restructure TODO.md with prioritized tasks and detailed organization
- Add PowerShell profile template for Windows platform support
- Split git configs into identity-specific templates (ryan/xevion)
- Convert nushell env.nu and gitconfig to templates for cross-platform rendering
- Refactor chezmoi hooks to TypeScript (.init_pre.ts, .update_pre.ts)
- Update .chezmoiignore with better platform-specific file handling
- Remove deprecated shellchecker.sh and tasks.json from VS Code config
- Add mise integration to shell configs (bash, zsh, nushell, PowerShell)
- Clean up commonrc.sh.tmpl WSL-specific code
- Disable Deno in VS Code settings, enable simple dialog mode
- Add nushell extension recommendation to VS Code

This commit establishes better cross-platform support (Windows/WSL/Linux),
improves documentation for future maintenance, and standardizes configuration
management patterns across the repository.

home/dot_gitconfig.tmpl

@@ -0,0 +1,56 @@
+# Git Configuration - Platform-aware
+# Managed by chezmoi
+
+{{ if eq .chezmoi.os "windows" }}
+# Windows Configuration
+[user]
+	name = Ryan Walters
+	email = ryan@walters.to
+	signingkey = 39538EC79ACF2597
+
+[commit]
+	gpgsign = true
+
+[gpg]
+	program = C:\\Users\\Xevion\\scoop\\apps\\gpg4win\\current\\GnuPG\\bin\\gpg.exe
+
+[credential "https://github.com"]
+	helper =
+	helper = !'C:\\Program Files\\GitHub CLI\\gh.exe' auth git-credential
+
+[credential "https://gist.github.com"]
+	helper =
+	helper = !'C:\\Program Files\\GitHub CLI\\gh.exe' auth git-credential
+
+{{ else }}
+# Linux/macOS Configuration
+[user]
+	name = Xevion
+	email = xevion@xevion.dev
+	signingkey = C217005CF3C00672
+
+[commit]
+	gpgsign = true
+
+[credential "https://github.com"]
+	helper =
+	helper = !/usr/bin/gh auth git-credential
+
+[credential "https://gist.github.com"]
+	helper =
+	helper = !/usr/bin/gh auth git-credential
+
+{{ end }}
+
+# Common configuration for all platforms
+[core]
+	editor = micro
+
+[init]
+	defaultBranch = master
+
+[filter.lfs]
+	required = true
+	clean = git-lfs clean -- %f
+	smudge = git-lfs smudge -- %f
+	process = git-lfs filter-process