fonline: Instructions file for Codex

FOnline Engine — Agent Instructions

This is the reusable Engine's maintainer entry point. Read it fully before Engine work, then open the owning guide. Human entry: README.md. Documentation: English index, Russian mirror. Keep this file concise; detailed contracts belong to their existing owners.

Working agreement

1. Confirm checkout/branch/diff/scope; preserve unrelated work. Re-anchor from source/plan/diff after handoff. Reports are evidence, not authority.
2. Read owners, validators and callers: source proves current behavior, owner requirements define intended behavior. Keep game policy/content/tooling outside Engine; fix reusable defects here instead of adding project workarounds.
3. Finish authorized verification; ask for material decisions or missing access. Establish every required source before multi-source synthesis.
4. No stage/commit/push/publication/deployment without action/scope authority. Past permission does not cover later tasks. Requested history integration may create its necessary merge. Stay on the requested branch; no generic-workflow branch churn.

Language: commits/prepared messages, PRs/issues, comments, diagnostics, plans and release notes are English. Russian docs translate English; chat language does not change this. Continue existing documents in their own language. No agent signatures.

Artifacts: task screenshots/logs/scripts/downloads/drafts/worker materials use Workspace/<task-id>/; follow an embedding project's explicit artifact root. Standard tool outputs retain their locations. No credentials/private raw sessions in versioned docs; sanitize evidence.

History, compatibility and documentation

• Rebase unpublished commits, preserve published history. Fetch origin/master before an authorized update, then rebase only unpublished local work. A branch's upstream or earlier pushes do not make its newer commits published. Merge only diverged published histories. No reset/amend/rebase of pushed commits, force-push or remote branch deletion. Before an authorized push, verify git merge-base --is-ancestor <destination-remote-tip> HEAD.
• Revision updates follow reconciliation: old/new SHAs, complete incoming range, owners/models and validation before dropping safety stashes. Check the embedding gitlink and Engine HEAD separately.
• Every master update follows versioning: derive the next minor from the latest published master, current UTC year, YEAR.MAJOR.MINOR-dev, dated EN/RU changes and exhaustive migration notes. All change types count. Release branches need an owner command; their cut freezes and advances patch. Local preparation does not authorize publication/commits.
• Current API, preserved meaning: valid inputs/outputs/units/IDs/defaults/side effects retain meaning. Replacements get distinct names/types/keys/formats and remove old surfaces. No deprecated aliases, shims, permissive parsing or masking; unmigrated consumers fail explicitly. ADR-0002 and migration records own the details.
• Serialized changes update ///@ MigrationRule; network/runtime compatibility changes bump the current central marker in Source/Common/Common.h. Never copy a historical number or accept mixed metadata bakes. Business migrations stay project-owned.
• Temporary old-build/platform/dependency restrictions use one ID/date across FO_TEMPORARY_COMPAT, [TemporaryCompat] or CMake TemporaryCompat; run BuildTools/temporary_compat.py. This never authorizes an old API bridge.
• Update owning docs and EN/RU/generated parity in the same change. Engine docs stand alone; projects may be examples, never normative validation dependencies. Follow documentation maintenance.