docs: add missing v8 to v9 migration guides

[Paolo Aliprandi (paolo-aliprandi)]

Summary

Adds and validates comprehensive v8-to-v9 migration documentation for mapped Fluent UI components.

• adds 28 component migration guides covering core, compatibility, renamed, and compositional replacements
• keeps the established migration-doc structure: concise overview, examples, prop mapping, and component-specific accessibility notes where needed
• covers aliases and variants such as Modal, ShimmeredDetailsList, VirtualizedComboBox, CommandBarButton, and PeoplePicker variants
• corrects stale component mapping entries and links every available migration guide
• reviews and aligns the existing migration documentation against current package exports, source types, and the new guide conventions

Guide coverage

Breadcrumb, Calendar, Callout, CommandBar, DatePicker, DetailsList, Dialog, Dropdown/Combobox, FocusZone/FocusTrapZone, Icon, Link, List, MessageBar, Nav, OverflowSet, Panel, Persona, ProgressIndicator, Rating, SearchBox, Shimmer, SwatchColorPicker, TagPicker/PeoplePicker, TeachingBubble/Coachmark, Text, TimePicker, Toggle, and Tooltip.

ComboBox is covered by the shared Dropdown/Combobox guide. Stack and Stack.Item are covered by the existing Flex guides, with StackShim and StackItemShim documented as temporary migration bridges.

Existing documentation alignment

• Component mapping and troubleshooting — normalized links, heading hierarchy, and portal guidance
• Card, Charts, ColorPicker, and Image — replaced stale imports, unsupported APIs, and incomplete theme/color examples
• Checkbox, Input, RadioGroup, Spinner, and Textarea — corrected prop names, ref targets, ARIA behavior, and invalid or incomplete examples
• Stack, Stack.Item, GroupedList, Tabs, and Keytips — aligned migration framing and headings, and fixed invalid TSX
• Theme and specialized Card/Flex/Image guidance — corrected shim availability, source links, and v8/v9 terminology while preserving specialized formats

Validation

• formatted with the repository Prettier configuration
• git diff --check
• validated all 53 component guides and 53 mapping links
• verified unique Storybook routes and exactly one title and top-level heading per guide
• verified 148 nonempty code fences and parsed all 134 TSX examples with the repository TypeScript version
• reviewed current package exports, prop/event types, compatibility packages, and accessibility semantics
• all required PR checks pass

Review focus

This remains a draft for component-owner review, especially for behavioral edge cases where v8 has no one-to-one v9 prop mapping and for compatibility-component guidance.

Current working directory: /Users/paoloaliprandi/Desktop/fluent-genui-benchmark

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📊 Bundle size report

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[github-actions]

Pull request demo site: URL

[Paolo Aliprandi (paolo-aliprandi)]

Reviewed the existing v8 → v9 migration documentation for consistency with the new guides:

• Component mapping and troubleshooting — links, heading hierarchy, and portal guidance were inconsistent; normalized the structure and linked every available migration guide.
• Card, Charts, ColorPicker, and Image — examples used stale imports, unsupported APIs, or incomplete theme/color patterns; updated them against current package exports and types.
• Checkbox, Input, RadioGroup, Spinner, and Textarea — prop names, ref targets, ARIA behavior, and examples were inconsistent or invalid; corrected the mappings and made the examples self-contained.
• Stack, Stack.Item, GroupedList, Tabs, and Keytips — migration framing, headings, or fenced examples differed from the established pattern; aligned the terminology and fixed the invalid Tabs TSX example.
• Theme and specialized Card/Flex/Image guidance — shim availability, source links, and v8/v9 terminology were stale; corrected the references while preserving their specialized formats.
• Regression coverage — expanded validation from the 28 new pages to all 53 component guides, covering unique routes, mapping links, title/H1 structure, nonempty code fences, and TSX syntax.