docs(agents): changelog is written only on the maintainer's explicit request

Claude-Session: https://claude.ai/code/session_017TK5JAYDfT3Fotc23UEg98

AGENTS.md

@@ -42,6 +42,7 @@ Shared contracts must define intentional behavior for every applicable runtime:
 - Do not add dependencies unless explicitly requested.
 - Never add or log secrets, bearer tokens, pairing credentials, or sensitive user data.
 - Keep changes minimal and preserve unrelated worktree changes.
+- `CHANGELOG.md` and `packages/vscode/CHANGELOG.md` are the maintainer's release-time work: they get written once, as one story, when the maintainer asks to update the changelog. Until that request, treat both files as read-only — a fix, feature, or merged PR lands without a changelog line.
 - Enforce security and correctness in core/runtime logic, not only UI visibility or prompts.
 - Keep entrypoints and bridges thin; place domain logic in focused owning modules.
 - Update owning documentation when module ownership, contracts, or invariants change.
@@ -100,7 +101,7 @@ process violation.
 | Settings UI, settings dialogs, configuration surfaces, or settings search | `settings-ui-patterns` |
 | Sortable or drag-to-reorder behavior, especially `@dnd-kit` and touch/wrapping layouts | `drag-to-reorder` |
 | iOS Simulator build, launch, preview, gestures, or `serve-sim` control | `serve-sim` |
-| Drafting or updating user-facing CHANGELOG entries for the `[Unreleased]` section (main app or VS Code extension) | `changelog-authoring` |
+| The maintainer explicitly asks to update the changelog (main app or VS Code extension) — the only time either CHANGELOG is edited | `changelog-authoring` |
 | Creating or editing skills, `AGENTS.md`, or docs reached through agent instructions/context pointers | `writing-for-agents` |
 | Reviewing a single pull request or drafting a PR verdict/close/review comment | `pr-review` |
 | Triaging, cleaning up, or batch-processing the open PR queue | `triage-prs` |