feat(ios): add skill for Capacitor 8.5 UIScene Migration

[ItsChaceD]

Description

Adds a capacitor-uiscene-migrator skill that assists with the Capacitor 8.4 → 8.5 UIScene migration, covering what npx cap migrate skips or only warns about: partially migrated projects, hand-rolled scene delegates, and custom application(_:open:) bodies. It audits before editing, asks at judgement points, merges into existing files instead of overwriting, and hands off to the CLI migrator when the project still matches the template shape.

SKILL.md plus four reference files (SceneDelegate template, audit patterns, merge recipes, plugin audit).

Change Type

• Fix
• Feature
• Refactor
• Breaking Change
• Documentation
• Other (CI, chores, etc.)

Rationale / Problems Fixed

ionic-team/capacitor#7961
ionic-team/capacitor#8536
ionic-team/capacitor#8544
https://outsystemsrd.atlassian.net/browse/RMET-5355

Tests or Reproductions

Ran the skill against four projects:

• Fresh 8.4 template app (classifies eligible, hands off to the CLI)
• SceneDelegate with a partial manifest (surgical merge, custom code verified preserved)
• AppDelegate with custom deep-link routing (asks before touching it, nothing silently dropped)
• Fresh Capacitor Plugin (audit only, flags the removed `tmpWindow)

Platforms Affected

• Android
• iOS
• Web

[alexgerardojacinto]

@ItsChaceD we should also add the skill to the README.md right?