fix: remove border on colored category tags

Colored variants were inheriting the neutral border from the base
rule, showing on hover when the fill shifted. Reserve border-width on
the base and let each variant opt into its own border-color.

Author: julioest

static/css/v3/category-tags.css

@@ -11,7 +11,7 @@
   cursor: pointer;
   transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
   color: var(--color-text-secondary);
-  border: 1px solid var(--color-tag-stroke);
+  border: 1px solid transparent;
 }
 
 .category-tag--default {
@@ -24,6 +24,7 @@
 
 .category-tag--neutral {
   background: var(--color-tag-fill);
+  border-color: var(--color-tag-stroke);
 }
 
 .category-tag--neutral:hover,
@@ -32,9 +33,14 @@
   color: var(--color-text-secondary);
 }
 
+.category-tag--green,
+.category-tag--yellow,
+.category-tag--teal {
+  color: var(--color-text-primary);
+}
+
 .category-tag--green {
   background: var(--color-surface-strong-accent-green-default);
-  color: var(--color-text-primary);
 }
 
 .category-tag--green:hover,
@@ -45,7 +51,6 @@
 
 .category-tag--yellow {
   background: var(--color-surface-strong-accent-yellow-default);
-  color: var(--color-text-primary);
 }
 
 .category-tag--yellow:hover,
@@ -56,7 +61,6 @@
 
 .category-tag--teal {
   background: var(--color-surface-strong-accent-teal-default);
-  color: var(--color-text-primary);
 }
 
 .category-tag--teal:hover,