feat: Initialize-GitDefaults.ps1 -- compose .gitattributes/.gitignore from upstream templates

.github/copilot-instructions.md

@@ -43,6 +43,12 @@ If a `*.template` file is present but the corresponding consumer-owned file
 is not, copy the template (drop the `.template` suffix) and fill in the
 sections. `Pull-SDLC.ai.ps1` does this automatically on first sync.
 
+For `.gitattributes` and `.gitignore`, run the repo-root script
+`Initialize-GitDefaults.ps1` (alongside `Pull-SDLC.ai.ps1`) to compose
+both files from per-language community templates plus a curated
+PowerShell block. `Pull-SDLC.ai.ps1` prints a one-line hint pointing at
+this script when either file is missing.
+
 ## Project Overview
 
 This is a **C#/.NET** project. Discover the project's purpose, architecture, and full

.github/templates/git-defaults/CSharp.gitattributes

@@ -0,0 +1,9 @@
+# Auto detect text files and perform LF normalization
+*          text=auto
+
+*.cs       text diff=csharp
+*.cshtml   text diff=html
+*.csx      text diff=csharp
+*.sln      text eol=crlf
+*.slnx     text eol=crlf
+*.csproj   text eol=crlf

.github/templates/git-defaults/Common.gitattributes

@@ -0,0 +1,98 @@
+# Common settings that generally should always be used with your language specific settings
+
+# Auto detect text files and perform LF normalization
+*          text=auto
+
+#
+# The above will handle all files NOT found below
+#
+
+# Documents
+*.bibtex   text diff=bibtex
+*.doc      diff=astextplain
+*.DOC      diff=astextplain
+*.docx     diff=astextplain
+*.DOCX     diff=astextplain
+*.dot      diff=astextplain
+*.DOT      diff=astextplain
+*.pdf      diff=astextplain
+*.PDF      diff=astextplain
+*.rtf      diff=astextplain
+*.RTF      diff=astextplain
+*.md       text diff=markdown
+*.mdx      text diff=markdown
+*.tex      text diff=tex
+*.adoc     text
+*.textile  text
+*.mustache text
+*.csv      text eol=crlf
+*.tab      text
+*.tsv      text
+*.txt      text
+*.sql      text
+*.epub     diff=astextplain
+
+# Graphics
+*.png      binary
+*.jpg      binary
+*.jpeg     binary
+*.gif      binary
+*.tif      binary
+*.tiff     binary
+*.ico      binary
+# SVG treated as text by default.
+*.svg      text
+# If you want to treat it as binary,
+# use the following line instead.
+# *.svg    binary
+*.eps      binary
+
+# Scripts
+*.bash     text eol=lf
+*.fish     text eol=lf
+*.ksh      text eol=lf
+*.sh       text eol=lf
+*.zsh      text eol=lf
+# These are explicitly windows files and should use crlf
+*.bat      text eol=crlf
+*.cmd      text eol=crlf
+*.ps1      text eol=crlf
+
+# Serialisation
+*.json     text
+*.toml     text
+*.xml      text
+*.yaml     text
+*.yml      text
+
+# Archives
+*.7z       binary
+*.bz       binary
+*.bz2      binary
+*.bzip2    binary
+*.gz       binary
+*.lz       binary
+*.lzma     binary
+*.rar      binary
+*.tar      binary
+*.taz      binary
+*.tbz      binary
+*.tbz2     binary
+*.tgz      binary
+*.tlz      binary
+*.txz      binary
+*.xz       binary
+*.Z        binary
+*.zip      binary
+*.zst      binary
+
+# Text files where line endings should be preserved
+*.patch    -text
+
+#
+# Exclude files from exporting
+#
+
+.gitattributes export-ignore
+.gitignore     export-ignore
+.gitkeep       export-ignore

.github/templates/git-defaults/Global/Backup.gitignore

@@ -0,0 +1,17 @@
+# Generic backup files
+*.bak
+*.back
+*.backup
+
+# Norton Ghost backup files
+*.gho
+
+# Generic original files
+*.ori
+*.orig
+*.original
+
+# Generic temporary files
+*.tmp
+*.temp
+*.temporary

.github/templates/git-defaults/Node.gitignore

@@ -0,0 +1,143 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional stylelint cache
+.stylelintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.*
+!.env.example
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+.parcel-cache
+
+# Next.js build output
+.next
+out
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+.output
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# vuepress v2.x temp directory
+.temp
+
+# Sveltekit cache directory
+.svelte-kit/
+
+# vitepress build output
+**/.vitepress/dist
+
+# vitepress cache directory
+**/.vitepress/cache
+
+# Docusaurus cache and generated files
+.docusaurus
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# Firebase cache directory
+.firebase/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# pnpm
+.pnpm-store
+
+# yarn v3
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions
+
+# Vite files
+vite.config.js.timestamp-*
+vite.config.ts.timestamp-*
+.vite/