fix(mobile): improve composer skill contrast

[Doctorthe113]

This is a small pr to improve contrast/readability on android app.
For example when in t3code (og) theme's dark mode, inline skill highlight is hard to read because it uses a light magenta color instead of high contrast dark color. Also glass surface doesnt really work well on android. It renders a translucent on the skill/command selector instead of a blurred surface. Resulting poor readability.

==== AI SLOP BELOW =====

Summary

• make Android command/skill selector surfaces opaque for readable content
• use black inline skill foreground in the T3 Code light and dark themes
• add a 2.5dp Android composer editor inset so skill borders are not clipped

Scope is limited to the Android/mobile composer UI.

Before

After

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This is a focused mobile UI adjustment affecting composer contrast, Android popover rendering, and editor spacing. It also changes the shipped light and dark theme defaults, warranting human review of the resulting product-wide visual behavior.

Not approved because:

• Monthly spending limit reached (workspace setting). Approvability relies on correctness review in order to determine eligibility

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