Add changelog entries with version 'next' to attributes modified by
PRs #261, #264, #265, #266, and #267. This tracks upcoming changes
for the next release across AI, tool, and deployment environment
attributes.

Co-Authored-By: Claude <noreply@anthropic.com>

Add a changelog field to attribute JSON files that tracks how each
attribute has changed across sentry-conventions release versions. This
includes the schema extension, a generation script that derives changelog
entries from git tags and commit history, updates to both TypeScript and
Python code generators, docs UI rendering, and validation tests.

Co-Authored-By: Claude <noreply@anthropic.com>

* style: Fix biome formatting and lint errors

Run biome formatter across all JSON model files to inline short arrays,
and replace non-null assertions with optional chaining or type casts to
satisfy biome's noNonNullAssertion rule.

Co-Authored-By: Claude <noreply@anthropic.com>

* feat: Merge changelogs instead of replacing on re-generation

Preserve manually added descriptions, hand-curated entries, and other
manual edits when re-running the changelog generation script. Previously
the script would completely replace existing changelog data on every run.

Add mergeChangelogs() that indexes by version, unions PR numbers,
preserves existing descriptions, keeps manual-only entries, and
re-sorts newest-first. Add unit tests covering edge cases.

Co-Authored-By: Claude <noreply@anthropic.com>

* feat: Add 'next' version support and changelog promotion on release

Support unreleased changes tracked as "next" entries in attribute changelogs.
When a new release tag is created, "next" entries are automatically promoted
to the new version while preserving manually-added descriptions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: Display changelog of attributes with 'next' version support

Show the attribute changelog in the AttributeCard component, including
entries with version 'next' (displayed without a 'v' prefix). Update
compareVersions to handle 'next' correctly and export it for reuse in
tests, removing the duplicate implementation.

Co-Authored-By: Claude <noreply@anthropic.com>

* ref(changelog): Simplify sort comparator and add perf TODO

Remove redundant 'next' guards in the sort comparator — compareVersions
already handles 'next' correctly, making those checks dead code.

Add a TODO comment noting the O(files × versions) git subprocess cost
and suggesting a future batch approach using `git diff --name-only`.

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(lint): Replace delete operator with undefined assignment

Biome's noDelete lint rule flags the delete operator for performance.
Since changelog is an optional field and JSON.stringify omits undefined
values, the behavior is identical.

Co-Authored-By: Claude <noreply@anthropic.com>

* feat(changelog): Add 'next' version changelog entries for attributes

Add changelog entries with version 'next' to attributes modified by
PRs #261, #264, #265, #266, and #267. This tracks upcoming changes
for the next release across AI, tool, and deployment environment
attributes.

Co-Authored-By: Claude <noreply@anthropic.com>

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Co-authored-by: Claude <noreply@anthropic.com>