fix: keep cache and form changesets on a minor release

[andrewzolotukhin]

Description / Original request

Keep the recent Framework cache/form work on a minor release rather than a major release, and open a new PR before continuing Xpenser.

What changed

• Change the server, client, and deep entries in .changeset/cache-form-correctness.md from major to minor; react-form remains minor.
• Change .changeset/defaulted-form-fields.md from patch to minor, consistent with this batch and its new public type exports.
• Add a release-classification note to the migration guide while retaining the cache-format and equality compatibility warnings.
• Leave the unrelated security-fix changeset, fixed-group configuration, package versions, lockfile, runtime code, and Xpenser unchanged.

Reasoning

A major entry in the fixed release group schedules all 19 Framework packages for 5.0.0. The corrected release plan schedules all 19 for 4.5.0, with no major releases. This changes the classification of this batch, not the general policy for future breaking changes.

The existing cache-key format and deepEqual behavior changes still require the documented consumer review/migration; relabeling the release does not make those compatibility concerns disappear.

Type of change

• Release metadata correction
• Documentation update
• Runtime/API change

Blog post

Skipped: internal release metadata, not a new user-facing feature.

Screenshots / preview evidence

Not applicable: no UI or runtime change. Framework CI has no PR preview deployment; the generated release plan is the relevant evidence.

Validation / Checklist

• npm ci --ignore-scripts
• npm run lint
• npm run build
• npm test — 4,267 tests across 178 files; no type errors
• npm run typecheck:schema-site
• npm run typecheck:docs-site
• npm run changeset -- status --output <temporary plan.json>, with assertions that all 19 fixed-group packages are minor releases at 4.5.0 and that the complete plan has no major release
• git diff --check
• Existing changesets corrected; no new package behavior requiring an additional changeset or runtime test
• GitHub Lint, Build & Test (Node 24) — passed
• E2e, browser screenshots, and SigNoz: skipped; no runtime/deployment change.
• PR-ready notification: skipped; this release-metadata PR has no preview/deployed environment URL.

No packages versioned/published and no PR merged.