Decouple `plugin:create` scaffolding from Shopware Core and simplify CLI UX

[lasomethingsomething]

User Story

As a developer, I want to generate plugin scaffolding independently of the Shopware Core version, so that I do not need to upgrade Shopware just to receive scaffolding fixes and can use the scaffolding across older Shopware versions.

Current State (Technical Context)

• Scaffolding is currently run via bin/console plugin:create.
• The command is registered in DI and uses tagged scaffold generators.
• Multiple generators dynamically extend options and questions.
• Generators are interactive and rely on CLI confirmations.
• Maker-based partial scaffolding already exists via make:*.
• Non-interactive mode currently has UX issues, including cases such as infinite loops.
• The command asks many questions during setup.
• Users often do not understand the consequences of individual choices or whether a feature can be added later.

Problems

• Scaffolding is tightly coupled to Shopware Core, so fixes require a Shopware upgrade.
• The interactive flow is too question-heavy and can feel overwhelming.
• Users lack clarity about the impact of certain options.
• There is no clear feedback loop after scaffold generation.
• App scaffolding is incomplete.
• Plugin scaffolding is only partially modular.
• It is unclear how widely the current feature is used.

Goals

1. Decouple scaffolding from Shopware Core

   • Provide scaffolding through a standalone PHP package or through shopware-cli.
   • Keep the Core command available; removal is not required.

2. Make scaffolding version-independent

   • Ensure it can be used with older Shopware versions.
   • Avoid requiring a Core rebuild or upgrade for scaffolding-related fixes.

3. Simplify the UX

   • Reduce the number of interactive questions.
   • Prefer explicit flags over confirmation prompts.
   • Improve discoverability through a clear --help output.
   • Clarify the consequences of selected options.
   • Make non-interactive mode fully deterministic.

4. Improve modularity

   • Separate the base scaffold from optional features.
   • Enable optional features explicitly through flags.
   • Avoid hidden cascading questions.
   • Either align with the make:* pattern, or deliberately avoid expanding maker-style commands and instead focus on one clear entry point such as shopware plugin create.
   • Keep the command surface minimal and predictable.

5. Introduce a CLI feedback loop

   • Optionally prompt for feedback or a survey after scaffold generation.

Acceptance Criteria

• Scaffolding is available independently of the Shopware Core version.
• Generated templates include schema JSON files so developers know they should update them when changing plugin APIs.
• Scaffolding works for older Shopware versions.
• Interactive prompts are reduced or optional.
• --help clearly lists all available scaffold features and options.
• Non-interactive mode behaves predictably and does not loop.
• App scaffolding parity is defined and any gaps are documented.
• A CLI feedback mechanism is implemented.
• The existing plugin:create command remains functional.

Out of Scope

• Removing plugin:create
• Refactoring the entire generator architecture
• Backporting large structural changes into Core

Related

• Full App Scaffold (Project-Level) #870
• Local Co-Hosted Dev Mode (Integration-Level) #871