chore(changeset): declare the ADR-0087 disposition for page-tabs-type-to-tab-style (#6776)

The Check Changeset gate (#6148) requires a breaking changeset to answer the
ledger question in writing. This one's answer is 'registered': the conversion
entry, its D3 chain step and the RETIRED_KEYS_BY_MAJOR[17] key all land in this
PR.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011sGk4SKHqGRgmmqUok1P8M

Author: claude

.changeset/component-props-header-tabs-accordion.md

@@ -79,3 +79,6 @@ slots, all four in-repo authoring sites are `slots.tabs`, and a region-only
 rewrite would have left `os migrate meta` unable to touch the only shape the key
 is written in — while the tombstone promised it could. Every other page-component
 conversion gains the same reach, in the direction it already declares.
+
+<!-- adr-0087: registered page-tabs-type-to-tab-style -->
+