#34

AGENTS.md

@@ -204,7 +204,7 @@ const value =
 ## Backend rules
 
 - Inspect existing routes, controllers, models, services, and specs before
-  editing backend behavior.
+  editing backend behaviour.
 - Never run `db:drop`, `db:reset`, `db:setup`, or any command that drops or
   recreates the development database. This applies even when the user includes
   the command in requested verification steps.
@@ -215,7 +215,7 @@ const value =
 - Repeated destructive instructions are not enough confirmation because they
   may be auto-generated. Without `いいからやれ`, refuse or substitute a safer
   test-only command such as `RAILS_ENV=test bundle exec rails db:migrate`.
-- For API behavior changes, add or update request specs under
+- For API behaviour changes, add or update request specs under
   `backend/spec/requests` only when the user explicitly asks for tests.
 - Prefer RSpec for new backend tests; existing minitest files under
   `backend/test` do not make minitest the default for new coverage.
@@ -223,8 +223,8 @@ const value =
 - Preserve the `X-Transfer-Code` user identification flow unless the task
   explicitly changes authentication.
 - Be careful with version tables, `version_no`, optimistic concurrency,
-  wiki revisions, and restore/diff behavior.
-- Be careful with tag names, tag normalization, implications, similarities, and discard behavior.
+  wiki revisions, and restore/diff behaviour.
+- Be careful with tag names, tag normalisation, implications, similarities, and discard behaviour.
 - Be sensitive to N+1 queries; avoid introducing them and proactively fix
   existing N+1 issues in the code path being edited.
 - Keep migration files and `backend/db/schema.rb` consistent when changing schema.
@@ -245,9 +245,9 @@ const value =
 - Internal links must use `PrefetchLink`.
 - External links must use `<a>` with `target="_blank"`.
 - When adding or changing Tailwind `bg-*` classes in TSX, pair them with an
-  explicit readable `text-*` color and dark-mode counterparts such as
+  explicit readable `text-*` colour and dark-mode counterparts such as
   `dark:bg-*`, `dark:text-*`, and `dark:border-*` where a border is present.
-- Do not rely on inherited text color for light backgrounds. This is especially
+- Do not rely on inherited text colour for light backgrounds. This is especially
   important for chips, cards, buttons, and panels that may inherit white text in
   dark mode.
 - Mobile UI must be checked as a first-class layout. Avoid wide fixed content,
@@ -355,9 +355,23 @@ const value =
 - Do not use a leading semicolon for expression statements such as
   `;([...]).forEach(...)`; rewrite the expression to avoid ASI hazards
   explicitly, for example with `void`.
-- Spell British English identifiers correctly when the feature name uses
-  British English. Use `Behaviour`, not `Behavior`, for new component and file
-  names unless editing an already established American-English API.
+- Use correct British English spelling for new identifiers, filenames,
+  component names, helper names, comments, and developer-facing prose unless
+  editing an already established American-English API that must keep its
+  existing spelling for compatibility.
+- Prefer British English spellings such as `behaviour`, `colour`, `realise`,
+  `theatre`, `centre`, `favourite`, `optimise`, and `catalogue`.
+- Avoid American or Canadian spellings such as `behavior`, `color`, `realize`,
+  `theater`, `center`, `favorite`, `optimize`, and `catalog`.
+- Even when an external library or API uses the wrong spelling, prefer to
+  correct it at the local boundary and use proper British English names in this
+  codebase. For example, prefer `import { color: colour } from '@external-lib'`
+  over spreading `color` through local code.
+- Apply the same boundary correction to object destructuring, wrapper helpers,
+  adapter layers, and local variable names when doing so does not break the
+  external contract.
+- For this repository, prefer names such as `BehaviourSettingsSection.tsx`, not
+  `BehaviorSettingsSection.tsx`.
 
 ### Frontend delimiter decision table
 
@@ -740,7 +754,7 @@ function PostFormTagsArea ({ tags, setTags }: Props) {
 - Do not scan or summarize dependency/generated/runtime directories such as
   `node_modules`, `dist`, `tmp`, `log`, and `storage` unless explicitly needed.
 - Before touching wiki, tag, versioning, BAN, IP BAN, or authentication
-  behavior, inspect the related request specs and service objects.
+  behaviour, inspect the related request specs and service objects.
 - If frontend code changes, run only non-test verification commands that
   apply, such as `npm run build` and `npm run lint`. Run `npm run test:run`
   only when the user explicitly asks for tests.
@@ -757,4 +771,4 @@ A task is complete only when:
   explained,
 - unrelated files are not changed,
 - migrations and schema are consistent when schema changes are made,
-- user-facing behavior is documented when needed.
+- user-facing behaviour is documented when needed.