feat: initial — fork skyrise for finance product

- Bakes in --warning / --warning-foreground (light + dark).
- Adds --text-hero size step (3.5rem) above display, for KPI heroes.
- Ships a .num utility (tabular-nums + slashed-zero + zero tracking).
- Redesigned dark-mode background: corner glows pushed to L≈0.30 with
  lower chroma over a clean near-black base — reads as soft brand-accent
  light instead of skyrise's muddy gamut-fringe blobs.
- Drops 11 background atmospheres + 4 surface tints — focused product theme.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/validate-theme.yml

@@ -0,0 +1,31 @@
+name: validate theme
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+
+      - name: Fetch validator + reference
+        run: |
+          mkdir -p .ci-scripts
+          curl -fsSL -o .ci-scripts/check-theme.mjs \
+            https://git.sky-ai.com/CremaUIStudio/core-interface/raw/branch/main/scripts/check-theme.mjs
+          git clone --depth 1 \
+            https://git.sky-ai.com/CremaUIStudio/lib-theme-pristine.git \
+            .ci-scripts/lib-theme-pristine
+
+      - name: Validate against pristine contract
+        run: |
+          node .ci-scripts/check-theme.mjs \
+            --target=theme.css \
+            --reference=.ci-scripts/lib-theme-pristine/theme.css \
+            --name=skyai-finance