Honor word-break and overflow-wrap in retained text layout

[wieslawsoltes]

Problem and result

WebScene wrapped retained text only at whitespace, so unchanged Code OSS long tokens overflowed Markdown preview, dialogs, notifications, hovers, hints, quick input, suggestions, REPL/debug surfaces, editor placeholders, comments, and chat/session UI even when their CSS requested word breaking.

This adds word-break, overflow-wrap, and the word-wrap alias across native/managed property metadata, cascade/CSSOM, inherited cold style state, UTF-8 safe retained fragmentation, fallback line wrapping, and min-content sizing. Long tokens now break at code-point boundaries while selection/highlight byte ranges remain ordered.

Closes #787. Parent epic: #235.

Quality and performance gates authored

• Candidate WPT contract for geometry, inheritance, CSSOM aliases, mutation/removal, and supplementary-plane text.
• Native retained-layout correctness regression.
• 4,096-node/ten-transition performance gate with a five-second budget and at most one layout pass per transition.
• Managed property-catalog and compiler alias regressions.
• Evidence/limitations report at docs/validation/code-oss-word-breaking-787.md.

Validation status

No build, test, WPT run, benchmark, visual comparison, package run, or CI result was executed under the current fast implementation instruction. Evidence is zero; the authored gates remain for consolidated qualification.