Implement interactive fallback flows for missing CLI parameters

[nick-pape]

Summary

The dev design states: "For some of these, e.g. component, solution name, component name, etc, if they are not specified we will fallback to an interactive flow." Currently, all required parameters (--template, --component-name, --library-name) are strictly required — omitting any causes an error with no interactive recovery.

Requirements

Interactive prompts for missing parameters

When the following parameters are not provided via flags, the CLI should interactively prompt for them:

Parameter	Prompt type	Notes
--template	List selection	Show available templates (from list-templates logic), let user pick
--solution-name	Text input	Prompt for solution name
--component-name	Text input	Prompt for component display name
--library-name	Text input	Could auto-derive from solution-name + component-name
--package-manager	Choice selection	npm / pnpm / yarn

Behavior

• Interactive mode is the default when running in a TTY
• When stdin is not a TTY (piped input, CI), missing required params should still error
• --ci-mode or similar flag should explicitly disable interactive prompts
• Prompts should have sensible defaults where possible (e.g., derive library-name from component-name)

UX flow (example)

$ spfx create
? Choose a template: (Use arrow keys)
  ❯ webpart-minimal - A minimal SPFx web part
    webpart-react - A React-based SPFx web part
    extension-application-customizer - An application customizer
    ...
? Solution name: my-solution
? Component name: Hello World
? Package manager: (npm)

Implementation notes

• Consider using inquirer or @inquirer/prompts for interactive prompts
• TTY detection: process.stdin.isTTY
• Each prompt should validate input inline (e.g., solution name format)
• After all prompts, show a summary and confirm before scaffolding

Dependencies

• list-templates (Implement list-templates CLI command #89) for template selection prompt
• --solution-name (Add --solution-name flag to create command #93) for the solution name parameter
• --package-manager (Add --package-manager flag to create command #94) for the package manager parameter

Acceptance criteria

• Running spfx create with no flags enters interactive mode in a TTY
• Each missing required parameter is prompted for
• Providing a flag skips its corresponding prompt
• Non-TTY environments error on missing required params
• Input validation occurs inline during prompting
• User can cancel (Ctrl+C) gracefully at any prompt

[nick-pape]

Closing — interactive flows are out of scope. All CLI parameters must be supplied via flags. The architecture spec has been updated to reflect this (commit a2ec1a3).