Change dashboard theme to Solarized

[dbcli-symphony]

Changes

• Updated the dashboard stylesheet to use Solarized light and dark palettes for page backgrounds, surfaces, text, borders, links, and semantic colors.
• Routed status pills, chat message states, live status states, modal overlay, and workflow flowchart colors through Solarized-aware CSS variables.

Tests

• ruff check .
• ruff format --check .
• mypy
• git diff --check
• pytest tests/test_cli.py tests/test_db.py -vv failed with sqlite3.OperationalError: attempt to write a readonly database.
• Full pytest did not complete in this VM after reporting the same failures and stalling in test_web_app.py.