copilot-instructions: Instructions file for GitHub Copilot

Purpose

• Standardize efficient VS Code workspace design for Codex and Copilot usage, especially when multiple windows are open on the same machine.
• Reduce duplicated indexing, Git scans, file watching, and extension host pressure without losing shared instruction discovery.

Core Rules

• Keep product workspaces focused on the active codebase only; do not add shared AI support folders to every project workspace.
• Shared instruction/runtime folders such as .github, .codex, copilot-instructions, and the global VS Code User folder belong in a dedicated configuration workspace, not in every product workspace.
• Do not rely on opening shared instruction folders just so Copilot can discover instructions; prefer global VS Code instruction locations pointing to the shared runtime paths.
• Treat umbrella workspaces with many heavy folders as temporary inspection tools, not as the default development workspace.

Template Compatibility

• Treat .vscode/settings.tamplate.jsonc as the global/user baseline, not as the exact content to duplicate inside each .code-workspace.
• Treat .vscode/settings.tamplate.jsonc as the source of truth for the global VS Code settings.json; render it into the user profile with scripts/runtime/sync-vscode-global-settings.ps1 instead of maintaining the global file by hand.
• Because VS Code does not support native inheritance from an external .vscode/settings.json into .code-workspace, use scripts/runtime/sync-workspace-settings.ps1 plus .vscode/base.code-workspace as the repository-supported pseudo-inheritance mechanism.
• Treat .vscode/base.code-workspace as the shared base for workspace-level extensions recommendations and any approved top-level defaults that should be inherited into generated workspaces.
• scripts/runtime/sync-workspace-settings.ps1 must merge the base workspace with the target workspace, preserve folders, preserve workspace-specific recommendations, and regenerate only the approved local override block.
• Generated .code-workspace files must inherit the repository-managed global baseline whenever possible and may intentionally be stricter only for approved local throttles that reduce machine pressure:
  • git.autorefresh = false
  • chat.agent.maxRequests reduced from the global default
• Keep global Git/SCM and extension throttles in the shared template:
  • git.autofetch = false
  • git.detectWorktrees = false
  • git.detectSubmodules = false
  • git.openRepositoryInParentFolders = never
  • extensions.autoUpdate = false
  • github.copilot.nextEditSuggestions.enabled = false
  • scm.repositories.visible kept conservative
• Keep high-cost repository metadata hidden and excluded globally:
  • hide .git and .vs from Explorer
  • exclude .git, .vs, TestResults, packages, BenchmarkDotNet.Artifacts, and .sonarqube from watcher/search scope
• Keep slow code-action providers conservative in the global baseline:
  • prefer eslint.codeActionsOnSave.mode = problems
  • disable ESLint quick-fix documentation and disable-rule comment actions by default
  • disable github.copilot.chat.reviewSelection.enabled when repeated code-action provider stalls are affecting editor responsiveness
• Keep the shared formatter baseline compatible with the repository EOF policy:
  • do not set esbenp.prettier-vscode as the shared global default formatter
  • do not set Prettier as the shared default formatter for javascript, typescript, html, css, scss, vue, json, or markdown
  • the repository default EOF policy uses insert_final_newline = false, while Prettier writes a terminal newline
  • keep shared editor.formatOnSave, editor.formatOnPaste, and editor.formatOnType disabled unless a narrower repository policy explicitly accepts formatter-managed EOF behavior
  • avoid language-scoped formatOnSave overrides in the shared global template when the formatter is known to normalize files with a terminal newline
  • repository-owned VS Code hooks should normalize edit-tool payloads before disk writes so AI edits do not reintroduce a terminal newline when the workspace policy forbids it
• Keep chat-session continuity settings aligned with the shared template:
  • workbench.startupEditor = welcomePage
  • chat.emptyState.history.enabled = true
• Keep window.restoreWindows = all in the user/global settings template; do not try to force this one through workspace-only policy.
• Do not copy unrelated editor, UI, formatter, language, or extension settings from the shared template into workspace scope when the global baseline already provides them.
• Do not duplicate files.watcherExclude or search.exclude in workspace scope when the global template already provides the required excludes.
• For generated workspaces, carry only approved local overrides; do not clone the global template into the workspace file.
• Do not attempt manual inheritance hacks inside .code-workspace files; the supported pattern is base workspace plus sync script.