[Bug]: PR #1776 alias validation breaks all community extensions — alias pattern not documented

[c05m1x]

Bug Description

Environment

• specify CLI version: 0.4.3

Problem

After the alias validation introduced in #1776, every community extension
that uses shorthand aliases fails to install:

specify extension add docguard
→ Validation Error: Invalid alias 'docguard.guard': must follow pattern 'speckit.{extension}.{command}'

specify extension add sync
→ Validation Error: Invalid alias 'speckit.drift': must follow pattern 'speckit.{extension}.{command}'

All community extensions fail. This is a regression introduced by #1776.

Impact

• All community extensions with aliases are broken
• No working workaround exists (local file paths rejected, localhost HTTP returns 400)
• Extension authors were not notified of the breaking change before it shipped

Expected behaviour

Either:

1. Aliases should be validated with a looser rule (or not validated at all), OR
2. Extension authors should have been notified before the breaking change shipped,
   with a migration guide

Suggested fix

• Add alias validation rules to the Extension Publishing Guide / RFC so authors
  know what is required
• Notify community extension authors of the new requirements
• Consider a grace period or warning instead of hard failure for alias violations

Steps to Reproduce

specify extension add verify --from https://github.com/ismaelJimenez/spec-kit-verify/archive/refs/tags/v1.0.1.zip

Expected Behavior

Extension installed

Actual Behavior

specify extension add verify --from https://github.com/ismaelJimenez/spec-kit-verify/archive/refs/tags/v1.0.1.zip
Warning: Installing from external URL.
Only install extensions from sources you trust.

Downloading from https://github.com/ismaelJimenez/spec-kit-verify/archive/refs/tags/v1.0.1.zip...

Validation Error: Invalid alias 'speckit.verify': must follow pattern 'speckit.{extension}.{command}'

Specify CLI Version

0.4.3

AI Agent

Claude Code

Operating System

macOS 15.7.5

Python Version

Python 3.14.3

Error Logs

Additional Context

No response