Preserve /// markers when wrapping long line comments

[arimu1]

Summary

Fixes #1369

wrapLineComments always continued wrapped line comments with //, and treated the non-breakable prefix as length 2. For /// comments that meant:

1. Long wrappable text continued with // in the middle of a /// block.
2. Long unbreakable tokens (e.g. markdown links with only a space after ///) were split into a bare /// line plus a // ... line containing the link.

Fix

In JavaCommentsHelper.wrapLineComments:

• Detect the leading slash run (//, ///, …) and reuse that marker on continuations.
• Treat the full marker length as non-breakable, matching existing // behavior so unbreakable content after /// is left as a single over-length line rather than mangled.

Tests

• FormatterTest.wrapTripleSlashLineCommentPreservesPrefix — wrappable /// text continues with ///
• FormatterTest.doNotBreakLongUnbreakableTripleSlashLink — regression for the issue example (100/101-char markdown links)
• Updated JavadocFormattingTest.simpleMarkdown expected output for non-javadoc /// lines (previously encoded the buggy // wrap)

Test plan

• mvn -pl core test on Temurin 25 — 1624 tests, 0 failures
• Targeted wrap tests on Temurin 21 — green
• Manual repro of issue sample (links inside method body) no longer injects //