feat: MUI 4 to BUI migration - add migration recipe workflow

[schultzp2020]

Summary

Add a misc migration recipe workflow that chains every deterministic MUI 4 to BUI codemod in a single ordered run for Backstage app and plugin repositories.

This recipe is not tied to a single Backstage release. It is the orchestration package for the ongoing MUI 4 to BUI migration work.

Release sequencing (required)

1. Implement and merge the codemod issues below (each with changeset -> Version Packages -> registry publish).
2. Only then implement and merge this recipe issue.
3. Do not publish the recipe to the registry until all dependency packages are published.

Recipe workflow steps must use source: '@backstage/<package>' (registry resolution), not local paths.

Recipe order (proposed)

#	Package	Domain
1	@backstage/migrate-mui-bootstrap-to-bui	Bootstrap / package setup
2	@backstage/migrate-mui-icons-to-remix-icons	Icon source migration
3	@backstage/migrate-mui-styles-to-bui-css-modules	Styling architecture
4	@backstage/migrate-mui-typography-to-text	Typography
5	@backstage/migrate-mui-alert-to-bui-alert	Alert banners
6	@backstage/migrate-mui-button-to-bui-button	Standard buttons
7	@backstage/migrate-mui-icon-button-to-button-icon	Icon buttons
8	@backstage/migrate-mui-tooltip-to-bui-tooltip	Tooltips
9	@backstage/migrate-mui-dialog-to-bui-dialog	Dialogs
10	@backstage/migrate-mui-tabs-to-bui-tabs	Tabs
11	@backstage/migrate-mui-menu-popover-to-bui-menu	Menus / popovers
12	@backstage/migrate-mui-list-family-to-bui-list	Lists
13	@backstage/migrate-mui-chip-to-tag	Tags / chips
14	@backstage/migrate-mui-select-family-to-bui-select	Select
15	@backstage/migrate-mui-textfield-to-bui-textfield	TextField
16	@backstage/migrate-mui-accordion-to-bui-accordion	Accordion
17	@backstage/migrate-mui-radio-checkbox-groups-to-bui-groups	Radio / checkbox groups
18	@backstage/migrate-mui-slider-to-bui-slider	Slider
19	@backstage/migrate-mui-layout-to-bui-layout	Layout primitives

Deliverables

• codemods/misc/mui4-to-bui-migration-recipe/ directory (package.json, codemod.yaml, workflow.yaml, README.md, CHANGELOG.md)
• Package name: @backstage/mui4-to-bui-migration-recipe
• README table listing each step with registry links and a short explanation of what each codemod covers
• Workflow version: '1' with sequential codemod: steps

Recipe behavior

• The recipe runs every codemod at default deterministic settings.
• The recipe ships no aiFixup parameter.
• Codemods should use TODO(backstage-codemod) markers rather than embedded AI workflow nodes for ambiguous cases.
• The README should document the expected manual follow-up pass after the recipe, including searching for remaining MUI imports and TODO markers.

Out of scope for recipe (document only in README)

• Timeline and unsupported Material UI Lab widgets without a stable BUI equivalent
• @material-table/core and broader table-system migrations that are not a safe 1:1 replacement
• Perfect theme parity, dark-mode polish, and final design-token tuning after the source-level migration
• Custom wrapper abstractions that hide MUI components behind project-specific APIs

QA target

Document dry-run against sample monorepo: ../backstage (C:/Users/pschu/Projects/backstage/backstage).

Changeset (when implementing)

• Package: @backstage/mui4-to-bui-migration-recipe
• Bump: minor (initial release)

Blocked by

• feat: MUI 4 to BUI migration - bootstrap app dependencies and root CSS #108 — @backstage/migrate-mui-bootstrap-to-bui
• feat: MUI 4 to BUI migration - replace MUI icons with Remix icons #109 — @backstage/migrate-mui-icons-to-remix-icons
• feat: MUI 4 to BUI migration - migrate makeStyles usage to BUI CSS modules #110 — @backstage/migrate-mui-styles-to-bui-css-modules
• feat: MUI 4 to BUI migration - convert common MUI layout primitives to BUI layout #111 — @backstage/migrate-mui-layout-to-bui-layout
• feat: MUI 4 to BUI migration - replace Typography with Text #112 — @backstage/migrate-mui-typography-to-text
• feat: MUI 4 to BUI migration - replace MUI Alert with BUI Alert #113 — @backstage/migrate-mui-alert-to-bui-alert
• feat: MUI 4 to BUI migration - replace MUI Button with BUI Button #114 — @backstage/migrate-mui-button-to-bui-button
• feat: MUI 4 to BUI migration - replace IconButton with ButtonIcon #115 — @backstage/migrate-mui-icon-button-to-button-icon
• feat: MUI 4 to BUI migration - replace Tooltip with TooltipTrigger #116 — @backstage/migrate-mui-tooltip-to-bui-tooltip
• feat: MUI 4 to BUI migration - replace Dialog shell with BUI Dialog #117 — @backstage/migrate-mui-dialog-to-bui-dialog
• feat: MUI 4 to BUI migration - replace MUI Tabs with BUI Tabs #118 — @backstage/migrate-mui-tabs-to-bui-tabs
• feat: MUI 4 to BUI migration - replace Menu and Popover patterns with BUI Menu #119 — @backstage/migrate-mui-menu-popover-to-bui-menu
• feat: MUI 4 to BUI migration - replace List family primitives with BUI List #120 — @backstage/migrate-mui-list-family-to-bui-list
• feat: MUI 4 to BUI migration - replace Chip with Tag #121 — @backstage/migrate-mui-chip-to-tag
• feat: MUI 4 to BUI migration - replace Select wrapper patterns with BUI Select #122 — @backstage/migrate-mui-select-family-to-bui-select
• feat: MUI 4 to BUI migration - replace TextField with BUI TextField #123 — @backstage/migrate-mui-textfield-to-bui-textfield
• feat: MUI 4 to BUI migration - replace Accordion with BUI Accordion #124 — @backstage/migrate-mui-accordion-to-bui-accordion
• feat: MUI 4 to BUI migration - replace radio and checkbox group patterns with BUI groups #125 — @backstage/migrate-mui-radio-checkbox-groups-to-bui-groups
• feat: MUI 4 to BUI migration - replace Slider with BUI Slider #126 — @backstage/migrate-mui-slider-to-bui-slider

Implementation notes

• Target directory: codemods/misc/mui4-to-bui-migration-recipe/
• Branch/worktree: .worktrees/feat/mui4-to-bui/mui4-to-bui-migration-recipe
• One PR; merge after the codemod issues are merged and published