Rollup: Tracking`aspire init` improvements and bug fixes

[maddymontaquila]

Summary

This is a rollup tracking issue for all open issues related to the aspire init command. The goal is to provide a single place to track the overall state of aspire init improvements, bugs, and feature requests.

Ideally, we move from the deterministic init model to a primarily agent-driven experience. We should make sure it addresses these issues while still completing the goal.

Bugs

• Running aspire init in empty folder fails #15750 — Running aspire init in empty folder fails (regression)
• Aspire init does not work with slnx #14045 — aspire init does not work with slnx
• Error when running aspire agent init from copilot CLI #15071 — Error when running aspire agent init from copilot CLI
• builder.AddServerDefaults() and builder.MapDefaultEndpoints() not placed in the correct spot #10255 — builder.AddServerDefaults() and builder.MapDefaultEndpoints() not placed in the correct spot
• TypeScript apphost scaffold: tsconfig.apphost.json not discovered by typescript-eslint project service #15852 — TypeScript apphost scaffold: tsconfig.apphost.json not discovered by typescript-eslint project service

Feature Requests

• Rethink 'aspire init' to optimize for coding agent success rather than file detection/scaffolding #15878 — Rethink aspire init to optimize for coding agent success rather than file detection/scaffolding
• aspire init should augment existing package.json for brownfield TypeScript apphosts #15122 — aspire init should augment existing package.json for brownfield TypeScript apphosts
• Support aspire init for Docker Compose files #11842 — Support aspire init for Docker Compose files
• Add an output flag to aspire init #12815 — Add an output flag to aspire init
• Add aspire init command to replicate enlist in orchestration features in VS/VSCode #8914 — Add aspire init command to replicate enlist in orchestration features in VS/VS Code
• aspire new should show how aspire new/init will mutate filesystem. #11535 — aspire new should show how aspire new/init will mutate filesystem