fix(ui): trim Tag's label text box so it shares a baseline with adjacent text

[billyvg]

Seer markdown block embeds show a tag in the header band, to the left of the
"View " link. The tag's label sat ~1.4px above the link's baseline.

Cause

Text, Heading, Link and InlineCode all set text-box-trim: trim-both,
so their boxes hug the glyphs. Tag did not — its label kept the font's
half-leading, and TagPill centers that taller box. Centering a line box
rather than the glyphs is what pushed the label up.

That also explains which embeds looked wrong: the ones passing a <Text> as
the badge (dashboardBlock, logBlock) already lined up; the six passing a
<Tag> (monitor, saved query, metrics, errors, spans, logs) did not.

Fix

Give TagText the same trim the rest of the text system uses.

Evidence

Measured in Chromium at 14px/Rubik, header band 36px, pill 20px — baseline
deltas relative to the link:

	tag → link	header title → link
before	1.41px	0.50px
after	0.50px	0.50px

The tag now sits exactly where the header's own title does. The remaining
0.5px is the inherent offset between co-centered 12px and 14px text; both
land on the same device pixel.

Scope

Tag is a core component, so this nudges the label ~1px down inside every
pill in the product — toward consistency with every other text primitive.
Worth a look from design if that's broader than wanted; the alternative is
scoping the same trim to the Seer embed header.

Tests

static/app/components/core/badge (4 suites) and the Seer embed suites
(seerEmbedBlock, monitor) pass; stylelint and oxfmt clean.

🤖 Generated with Claude Code

[github-actions]

Story previews

Preview the stories changed in this PR on the Vercel deployment:

• app/components/core/badge/badge.mdx
• app/components/core/badge/tag.mdx

_{Preview deployment: https://sentry-34dguioj5.sentry.dev}