fix(cv/v2): visual breathing room — entry separation + MP body left-padding

[DemchaAV]

Reader feedback after CV review of the rendered v2 PDFs:

1. Education / Experience / Projects sections rendered as a wall of text — consecutive university entries, jobs, and projects shared the same line spacing as their internal lines, so the boundary between one entry and the next was visually invisible.

2. In ModernProfessional preset, body text was flush with the section title (no left indent) — section title sat at the same x-coordinate as the body beneath it, making the visual hierarchy weaker than v1 had.

Fix

1. CvSpacing.entrySeparation — new spacer between consecutive multi-line entries.

• classic preset: 6pt
• modernProfessional preset: 8pt
• @Deprecated 13-arg constructor preserved for backward-compat — fills new field with 6pt default

2. SectionDispatcher inserts host.spacer(0, entrySeparation) between items for:

• EntriesSection — always (Education, Experience are multi-line)
• RowsSection with BULLETED_STACKED style — between project items
• Single-line styles (PLAIN, BULLETED) unaffected — already breathe via paragraphMarginTop

3. CvSpacing.modernProfessional() sectionBodyPadding left: 0 → 12pt — body text now visually indents from blue section title.

Baselines refreshed

All 6 visual-baseline PNGs refreshed via the -Dgraphcompose.visual.approve=true workflow established in #52. This commit is the first deliberate consumer of that workflow, demonstrating it works exactly as designed:

1. Make visual change
2. Visual parity test fails locally → check the actual vs diff PNGs
3. Re-bless via approve flag
4. Commit refreshed baselines alongside the code change

What's NOT changed

• Engine and v1 surface untouched.
• Public v2 API additions are backward-compatible (@Deprecated old ctor on CvSpacing).
• All other section types (Paragraph, PLAIN/BULLETED rows) render identically.

Test plan

• 3/3 CvV2VisualParityTest pass against refreshed baselines
• All other v2 tests green
• Re-rendered cv-modern-professional-v2.pdf — body indented, entries separated
• CI green

⚠️ Stacked on #52 (visual-regression infra). After #52 merges, this PR's diff shrinks to just the spacing change + baseline updates.