[codex] fix mobile panel theme inheritance

[kachofugetsu09]

What changed

• replace plugin-private hardcoded colors with shared Akashic Material semantic token pairs
• reduce the compact-screen headline tile height and type size
• add a regression test that rejects raw color literals in the mobile panel

Why

The live Pixel 7 and Pixel 9 panels rendered oversized, highly saturated cards that did not follow the selected host theme. The data query and plugin route were healthy; the plugin CSS owned the visual regression.

Impact

Only the plugin-owned mobile panel presentation changes. Query payloads, proactive state, history, and plugin lifecycle are unchanged.

Validation

• node --test tests/test_mobile_panel.mjs (5 passed)
• /mnt/data/coding/akasic-agent/.venv/bin/python -m pytest -q (14 passed)
• git diff --check
• reproduced on a real Pixel 7 running Akashic Mobile 0.8.33-rc.5 before deployment