feat(cv-v2): hyperlink-aware ProjectRenderer + ProjectLabel (M3, @since 1.6.8)

[DemchaAV]

Summary

Closes the v1.6.8 markdown-link feature end-to-end. With M1
(#119) the
parser knew about [label](url); after this PR the CV /
cover-letter ProjectRenderer actually emits a clickable
hyperlink when a project row's label is authored as Markdown.

ProjectLabel refactor

• Old parse() ran MarkdownInline.plainText() first, then
  split on the last (. That stripped emphasis AND links
  up-front, so the link URL was lost before the renderer ever
  saw it.
• New parse() targets a trailing \s+\([^()]*\)\s*$ pattern
  only. Result: the title field preserves the original
  Markdown syntax ([name](url) or **bold** etc.) and is
  rendered later through MarkdownInline.append. The stack-paren
  pattern requires whitespace before its opening paren, so a
  leading [name](url) URL's own (...) segment is not mistaken
  for the stack delimiter.

Input	Title	Stack
"GraphCompose (Java, PDFBox)"	"GraphCompose"	"Java, PDFBox"
"[GraphCompose](url) (Java)"	"[GraphCompose](url)"	"Java"
"[GraphCompose](url)"	"[GraphCompose](url)"	""
"**GraphCompose**"	"**GraphCompose**"	""

ProjectRenderer wiring

• ProjectRenderer.inline(...) and .titleThenBody(...) now
  call MarkdownInline.append(rich, label.title(), titleStyle)
  instead of rich.style(label.title(), titleStyle). Plain-text
  titles render identically to before (the emphasis pipeline
  emits one styled run); Markdown titles emit emphasis / link
  runs.
• ProjectRenderer.plainInline(...) (one-line listing variant)
  intentionally continues to drop link syntax via
  MarkdownInline.plainText(...) because a clickable hyperlink
  would not survive the compact formatting context. This is the
  variant used by sidebar / minimal presets.

Compatibility

• ProjectLabel.parse return shape is unchanged (still a
  two-field record). The semantic of title() changes: it now
  keeps inline Markdown rather than returning a pre-flattened
  plain-text projection. That fixed the one in-repo test that
  pinned the old abstraction-leak:
  CvV2ComponentUtilityTest.projectLabelSplitsTrailingStack was
  relying on parse() stripping ** markers up-front; the test
  is updated to assert the new shape with an inline comment
  pointing at ProjectLabelTest for the full coverage.
• Visual baselines: existing CV v2 visual-parity baselines render
  unchanged because the canonical CvDocument fixture does not
  use inline Markdown in project labels. The new path is
  exercised by the test additions below.

Test plan

• New ProjectLabelTest (8 tests) — pins legacy "Project
  (Stack)" parse, link-only label, link + stack, URL-paren-
  vs-stack-paren disambiguation, null/whitespace handling.
• MarkdownInlineTest from M1 covers the link-run emission
  path itself.
• CvV2ComponentUtilityTest.projectLabelSplitsTrailingStack
  updated to assert the new shape (**GraphCompose**
  preserved in title).
• ./mvnw verify -pl . -P japicmp — 1057 tests, 0 failures.
  japicmp vs v1.6.7 baseline: semver PATCH (compatible
  internal rewiring on public methods; no signature change,
  return-shape is identical).