FN-6149: tokenize bare hex colors in dashboard CSS

Replace hard-coded dashboard hex colors with semantic tokens and guard the cleanup with regression coverage.

- swap bare hex colors in ScriptsModal.css for semantic custom properties
- swap bare hex colors in SettingsSyncLog.css for semantic custom properties
- add regression coverage for bare hex literals outside var() fallbacks in audited dashboard CSS
- add a patch changeset for @runfusion/fusion

Files changed:
 .changeset/fn-6149-css-tokenization.md               |  5 +++++
 .../dashboard-component-color-tokenization.test.ts   | 20 ++++++++++++++++++++
 packages/dashboard/app/components/ScriptsModal.css   |  4 ++--
 .../dashboard/app/components/SettingsSyncLog.css     |  4 ++--
 4 files changed, 29 insertions(+), 4 deletions(-)

Fusion-Task-Id: FN-6149

Fusion-Task-Lineage: 3a3ae466-7e53-484a-8785-c15a7f83aca7

packages/dashboard/app/components/ScriptsModal.css

@@ -4074,7 +4074,7 @@
 .changes-diff-patch .diff-hunk,
 .gm-diff-patch [data-prefix="@@"],
 .changes-diff-patch [data-prefix="@@"] {
-  color: #58a6ff;
+  color: var(--color-info, #58a6ff);
 }
 
 /* Block display for highlighted diff lines */
@@ -4110,7 +4110,7 @@
 [data-theme="light"] .changes-diff-patch .diff-hunk,
 [data-theme="light"] .gm-diff-patch [data-prefix="@@"],
 [data-theme="light"] .changes-diff-patch [data-prefix="@@"] {
-  color: #0969da;
+  color: var(--color-info, #0969da);
 }
 
 /* Light theme changed-files modal overrides */