Enable parley line-box strut and plumb vertical-align for inline boxes

[nicoburns]

Summary

Blitz-side plumbing for the parley strut/vertical-align stack (DioxusLabs/parley#9 → #10 → #7), which fixes two WPT regression groups from the parley 0.10 → 0.11 upgrade (negative half-leading clamped away; no strut on text-less lines):

• Re-pins parley to bb7159a (the stack head).
• build_inline_layout_into calls builder.set_compute_strut(true) so every line box is sized as if it began with a zero-width glyph in the root style (the CSS 2 § 10.8 "strut").
• Maps Stylo's baseline-shift: top/bottom keywords onto the new InlineBox::vertical_align field; everything else stays Baseline.
• Mechanical adaptation to the new append_inline_box_to_line(next_x, Option<InlineBoxAlignment>, quantize) signature (out-of-flow boxes pass None so they no longer contribute (0, 0) extents that clamp negative leading).

WPT results (manual run)

css/CSS2 + css/css-fonts + css/css-backgrounds + css/css-text (8868 tests) vs the unmodified devin/1786131935-parley-git-dep branch: 5038 passing vs 4948 before — 98 newly passing, 8 newly failing. Newly passing covers the line-height-* cluster (Group B), text-less-line strut tests (Group C1), first-available-font-003/004, and the floats-wrap-bfc-002-* vertical-align: bottom tests (Group C2).

Still failing / newly failing (pre-existing Blitz limitations exposed by the strut, not special-cased):

• css/CSS2/fonts/font-family-applies-to-005.xht (C4: 1px metric quantization)
• css/css-break/ruby-003.html, css/css-ruby/br-clear-all-000.html (C3: ruby)
• 6× css/CSS2/lists/list-style{,-image,-type}-applies-to-01{2,4}.xht — empty list-item markers don't create a line box, so the now-correct baseline alignment of the empty inline-block wrapper shifts the marker
• css/CSS2/normal-flow/inline-table-width-002b.xht — inline-table baseline (Group A territory)
• css/css-fonts/font-colorization.html — first-available-font selection needs unicode-range support (Blink treats a face with no unicode-range as covering U+0020 regardless of its cmap)

Link to Devin session: https://dioxus.staging.devinenterprise.com/sessions/6ab608fbe6fb46479d6dab03fedceb25
Requested by: @nicoburns

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