fix(test): update P8 baseline for --sf-color-selection-bg dark branch

After the dark branch of --sf-color-selection-bg was corrected to use
--sf-color-action-source-dark (instead of -source-light), the resolved
value changes from oklch(0.5 0.22 235) to its auto-derived dark
equivalent oklch(0.7 0.198 235). Update both the light-section
light-dark() expression and the dark-section resolved entry.

Author: claude

tests/baseline-modern.json

@@ -20,7 +20,7 @@
     "--sf-color-border--subtle": "light-dark(\n        oklch(from oklch(0.52 0.025 260) clamp(0.75, calc(l + 0.4),  0.97) 0.005 h),\n        oklch(from oklch(0.52 0.025 260)       clamp(0.20, calc(l - 0.38), 0.45) 0.005 h)\n      )",
     "--sf-color-border--strong": "light-dark(\n        oklch(from oklch(0.52 0.025 260) clamp(0.55, calc(l + 0.1),  0.85) 0.02  h),\n        oklch(from oklch(0.52 0.025 260)       clamp(0.38, calc(l - 0.1),  0.65) 0.02  h)\n      )",
     "--sf-color-link": "light-dark(\n        oklch(from oklch(0.5 0.22 235) clamp(0, min(l - 0.07, 0.48), 1) c h),\n        oklch(from oklch(0.5 0.22 235) clamp(0.68, l, 1) c h)\n      )",
-    "--sf-color-selection-bg": "light-dark(\n        oklch(from oklch(0.5 0.22 235) l c h / 0.28),\n        oklch(from oklch(0.5 0.22 235) clamp(0.62, calc(0.93 - l * 0.4), 0.78) c h / 0.55)\n      )",
+    "--sf-color-selection-bg": "light-dark(\n        oklch(from oklch(0.5 0.22 235) l c h / 0.28),\n        oklch(from oklch(0.7 0.198 235) clamp(0.62, calc(0.93 - l * 0.4), 0.78) c h / 0.55)\n      )",
     "--sf-color-success-strong": "light-dark(\n        oklch(from oklch(0.5 0.16 145) calc(l - 0.15) c h),\n        oklch(from oklch(0.5 0.16 145)       clamp(0.70, calc(l + 0.15), 1) c h)\n      )",
     "--sf-color-warning-strong": "light-dark(\n        oklch(from oklch(0.75 0.17 80) calc(l - 0.25) c h),\n        oklch(from oklch(0.75 0.17 80)       clamp(0.70, calc(l + 0.05), 1) c h)\n      )",
     "--sf-color-info-strong": "light-dark(\n        oklch(from oklch(0.48 0.18 235) calc(l - 0.1) c h),\n        oklch(from oklch(0.48 0.18 235)       clamp(0.70, calc(l + 0.15), 1) c h)\n      )",
@@ -51,7 +51,7 @@
     "--sf-color-border--subtle": "oklch(from oklch(0.69 0.0225 260) clamp(0.20, calc(l - 0.38), 0.45) 0.005 h)",
     "--sf-color-border--strong": "oklch(from oklch(0.69 0.0225 260) clamp(0.38, calc(l - 0.1),  0.65) 0.02  h)",
     "--sf-color-link": "oklch(from oklch(0.7 0.198 235) clamp(0.68, l, 1) c h)",
-    "--sf-color-selection-bg": "oklch(from oklch(0.5 0.22 235) clamp(0.62, calc(0.93 - l * 0.4), 0.78) c h / 0.55)",
+    "--sf-color-selection-bg": "oklch(from oklch(0.7 0.198 235) clamp(0.62, calc(0.93 - l * 0.4), 0.78) c h / 0.55)",
     "--sf-color-success-strong": "oklch(from oklch(0.7 0.144 145) clamp(0.70, calc(l + 0.15), 1) c h)",
     "--sf-color-warning-strong": "oklch(from oklch(0.65 0.153 80) clamp(0.70, calc(l + 0.05), 1) c h)",
     "--sf-color-info-strong": "oklch(from oklch(0.71 0.162 235)    clamp(0.70, calc(l + 0.15), 1) c h)",