docs: reserve seam for complete capabilities

packages/client/ui-primitives/tests/diff-block.spec.tsx

@@ -4,7 +4,7 @@
 // its singular/plural, the head/tail height cap and its expand control, the
 // empty-diffs null render, and the copy control writing the prefixed diff text
 // on both the accepted and the refused clipboard paths. writeClipboard's own
-// return contract is pinned in terminal-block.spec.tsx (the shared seam), so
+// return contract is pinned in terminal-block.spec.tsx (the shared return contract), so
 // only its DOM consequence is asserted here.
 
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'

packages/client/ui-primitives/tests/terminal-block.spec.tsx

@@ -3,7 +3,7 @@
 // arms, the prompt line's run-state dot, the exit-status pill, the head/tail height cap and its expand control,
 // and the copy control writing the raw output on both the accepted and the
 // refused clipboard paths. writeClipboard's own return contract is pinned here
-// too, since it is the seam both copy controls in this package share; the
+// too, since it is the return contract both copy controls in this package share; the
 // resolution of ANSI runs into styles is pinned in ansi.spec.ts, so only its
 // DOM consequence (which runs get a span wrapper) is asserted here.