Compat Kit: exclude named nested classes under anonymous owners

[swear01]

Context

Immersive Engineering 12.4.2-194 contains a named nested class under an anonymous owner (ModelConveyor$1$Key). Compat Kit scanner format 16 currently treats the named child as source-addressable, then fails because the anonymous owner has no truthful source-level name. This blocks the exact format-16 migration required by #53.

Required behavior

• Follow the complete InnerClasses owner chain before treating a nested class as source-addressable.
• Exclude a named child when any owner is anonymous, local, or synthetic.
• Never invent a source-level owner/name such as ModelConveyor.Key.
• Preserve legal top-level identifiers containing $ and normal named nested classes.
• Invalidate pre-fix classifier caches.

Acceptance

• Strict-TDD regression for ModelConveyor$1$Key: RED on current main, GREEN after the fix.
• Existing named/top-level $, anonymous/local/synthetic, source mapping, and cache tests remain green.
• Full Compat Kit Python suite passes after exact ancestry staging.
• Active Compat Kit/addon-development docs describe the source-addressability rule.
• Latest-head CI and one manually triggered GitHub review bot pass before merge.

Blocks #53. Umbrella: #33.