docs(releases): finalize the 17.5.0 notes after publish

17.5.0 was published to the `latest` tag on 2026-09-29. Resolve the
release-time TODOs the pre-cut draft carried:

- the publish date, 20 days after 17.4.0;
- the count: the version commit 8c87d26 consumed 958 changesets, not the
  868 pending at ab6fb02; the 17.5.0 CHANGELOG sections list them as 1,372
  per-package entries in 56 of 69 files, de-duplicating to the same 958;
- the 90 changesets consumed that the draft never read, folded into
  Highlights, Breaking changes & migration, New capabilities, Notable fixes
  and New in Console, with checklist lines marked not exercised;
- the fourth objectui pin move, f8a9d0f -> dd3f7e1;
- nodemailer ^10.0.2 (GHSA-6vj9-mwq6-2f5v) and its requireTLS note;
- a subsection for the eight commits the publish carried past the version
  commit, with a migration note for the breaking 92fe081 (#20613);
- v17/index.mdx: 17.5.0 released and current, its register paragraph,
  the per-release list and the checklist links.

Claude-Session: https://claude.ai/code/session_014VGCS11YUtYAiinRcdqQwL
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude