No-AI skill tracer: SKILL.md, theme presets, sample data, Seam 1 page check

- rpa-dashboard-no-ai/SKILL.md: trigger description and the workflow in spec
  order (scan, report/keep-or-restyle, colours, stack, sections, build, wire,
  verify).
- templates/themes.md: Tebra Sky and Superbill Ember, light and dark blocks.
- templates/palette.py: derives a custom palette from one brand hex and
  checks text contrast in light and dark.
- dashboard.html: built-in sample data so a page with no bot works on first
  open; cleared batches in the donut; component tokens so Ember is a
  token-only swap; accessible names for KPI cards, nav, steps, log, search
  and the dark toggle.
- bridge.py: placeholders inside string literals, so it passes the lint hook
  unfilled.
- tests/page_check: Seam 1 harness (fake Qt bridge, light/dark/narrow).
- tests/evals: Seam 2 runner and fixture a-empty.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/fixtures/a-empty/README.md

@@ -0,0 +1,4 @@
+# Fixture (a): empty project
+
+No frontend and no bot. The no-AI skill should report no frontend, ask for colours,
+the stack and optional sections, and produce a page that runs on sample data.