fix(FN-916): fix invisible edit icons in Git Manager Remotes panel

- Fix edit icon color in GitManagerModal Remotes section to use visible contrast color
- Add CSS rule for .git-manager-edit-btn to ensure icon visibility
- Changes affect GitManagerModal.tsx and styles.css

packages/dashboard/app/components/GitManagerModal.tsx

@@ -1955,7 +1955,7 @@ function RemotesPanel({
                       disabled={remoteActionLoading !== null}
                       title="Rename remote"
                     >
-                      <GitBranchIcon size={12} />
+                      <GitBranchIcon size={12} color="var(--text-muted)" />
                     </button>
                   </div>
                 )}
@@ -2009,7 +2009,7 @@ function RemotesPanel({
                         disabled={remoteActionLoading !== null}
                         title="Edit URL"
                       >
-                        <FileEdit size={12} />
+                        <FileEdit size={12} color="var(--text-muted)" />
                       </button>
                     </div>
                   )}