refactor(i18n): migrate packages/i18n from MobX to react-i18next (#8898)

* refactor(i18n): migrate packages/i18n from MobX to react-i18next with per-feature namespaces

Replaces the internals of packages/i18n with react-i18next while preserving the
identical public API. Consumer code using useTranslation() and TranslationProvider
requires no changes.

Translation file format: TS objects to JSON namespaces
- Converted TypeScript translation files (19 languages) into feature-based JSON namespace files
- Split the monolithic translations.ts into per-feature namespace files: workspace.json,
  project.json, work-item.json, cycle.json, inbox.json, etc.
- 30 community namespaces across 19 languages = 570 JSON files

Core runtime: MobX to i18next
- Replaced MobX TranslationStore with an i18next instance using i18next-icu
  (preserves ICU MessageFormat) and i18next-resources-to-backend (namespace lazy loading)
- useTranslation() and TranslationProvider keep identical signatures
- All namespaces pre-loaded during init for the current language to prevent
  re-render cascades
- Reads saved language from localStorage before init for faster first paint

Build tooling
- scripts/generate-types.ts: Reads English JSON files and outputs keys.generated.ts
  with a flat union of translation keys (runs before every build)
- scripts/sync-check.ts: Cross-locale missing/stale key detection, cross-namespace
  collision detection, path conflict detection (supports --ci mode)

App-level changes
- Removed useTranslation-based language sync effect from store-wrapper
- Language is now synced imperatively from profile.store (fetchUserProfile,
  updateUserProfile) and root.store (resetOnSignOut) via setLanguage()

Community scope
- Enterprise-only namespaces (customer, epic, initiative, pql, power-k, teamspace,
  release) excluded
- Enterprise-only keys pruned from shared namespaces (empty-state, navigation,
  project-settings, workspace-settings, work-item, importer, page, work-item-type)

* fix(i18n): restore parity with community preview after namespace refactor

The community port of plane-ee#6449 (MobX -> react-i18next refactor) had
gaps that broke ~25 unique translation keys community code calls. This
commit restores parity:

- Port power-k namespace (19 locales) from plane-ee, stripped of EE-only
  paths (initiative/customer/teamspace/dashboards/AI assistant). Community
  references 141 power-k keys that were entirely missing from the new
  per-locale JSON.
- Restore epic.* keys (8 leaves) into work-item.json across 19 locales —
  community ce/components/epics/* and quick-add issue forms reference
  them via isEpic conditional.
- Add 'date' leaf to common.json across 19 locales (sourced from
  work_item_types.settings.properties.property_type.date.label so the
  proper translation, not English, is used).
- Move exporter.* subtree from importer.json to common.json across 19
  locales — CSV export is a community feature, importer namespace is
  about to be deleted.
- Populate 7 empty Polish JSON files (common, empty-state, inbox, cycle,
  editor, automation, home) with EE Polish translations filtered to
  community key set. The community port committed these as 0-byte files.
- Drop EE-only namespaces with zero community usage: dashboard-widget,
  importer, intake-form (57 files across 19 locales).
- Update NAMESPACES const: drop the 3 deleted namespaces, add power-k.
- Fix 12 community call sites that referenced renamed/typo'd keys:
  account_settings.api_tokens.heading -> .title
  auth.common.password.toast.error.* -> .change_password.error.*
  sign_out.toast.error.* -> auth.sign_out.toast.error.*
  notification.toasts.un_snoozed -> .unsnoozed
  profile.stats.priority_distribution.priority -> common.priority
  projects.label -> common.projects
  progress -> common.progress
  epics -> common.epics
  creating_theme -> common.saving (no localized source available)
  toast.error (with trailing space typo) -> toast.error

Verified: every literal t(...) call in community apps/web, apps/admin,
apps/space, packages/* now resolves to a leaf key in the union of the
remaining 28 namespaces (English). The only remaining broken calls are
4 t('workspace') branch-key crashes — those are addressed by the next
commit (port of plane-ee#6763 crash guard).

Refs: makeplane/plane-ee#6449

* fix(i18n): guard t() against namespace-node returns to prevent React crashes

Wraps useTranslation()'s t() in coerceToString so namespace-node lookups
(which i18next-icu unconditionally returns as raw objects regardless of
returnObjects:false) fall back to the key string instead of crashing
React with 'Objects are not valid as a React child'.

Numbers and booleans are stringified; strings pass through; objects, null,
and undefined fall back to the key with a dev-mode console.warn pointing
to the bad call site. Production builds suppress the warning but keep the
guard. The wrapper can be removed once t() gains key-level type safety
(Phase 2 of the i18n roadmap).

Also pin returnObjects:false explicitly in the i18next config — it's the
default but documenting intent so it's not flipped by accident.

Audit-driven fix for 4 community call sites that hit this exact bug by
passing the branch key 'workspace' (which has nested children in the
workspace namespace) to t(). Switched to t('common.workspace') (existing
leaf with value 'Workspace').

Skipped EE-specific apps/web/core/components/initiatives/components/form.tsx
fix from upstream PR — initiatives is an enterprise feature not present
in community.

Refs: makeplane/plane-ee#6763

* chore(i18n): gitignore auto-generated translation key types

keys.generated.ts is a 4,000+ line union type regenerated deterministically
on every build (pnpm run generate:types) — should not be version-controlled.

Adding the file to .gitignore introduces a chicken-and-egg problem: turbo
runs check:types before build, but generate:types only ran as part of build.
On a fresh clone with no keys.generated.ts present, tsc --noEmit fails. Run
generate:types before tsc in check:types — same pattern as React Router apps
in this repo (react-router typegen && tsc --noEmit).

- Add packages/i18n/src/types/keys.generated.ts to root .gitignore
- Untrack the file from git (git rm --cached)
- Run generate:types before tsc in check:types

Verified: deleting keys.generated.ts and running check:types regenerates
the file correctly. After regeneration, git status shows the file remains
untracked (.gitignore is honored).

Refs: makeplane/plane-ee#6784

* fix(i18n): translate settings sidebar category headers

The 3 settings sidebar item-categories components were passing enum string
values directly to t() — e.g. t('your profile'), t('work-structure'),
t('administration'). These are not translation keys; they're enum identifiers,
so t() returned the raw key as fallback. Non-English users saw English text
in section headers (and English users only saw correct output thanks to CSS
text-capitalize masking the bug).

Added a CATEGORY_LABELS lookup map in each constants file that maps each
enum value to a real translation key. Components now call t(LABELS[category])
instead of t(category).

- Added 5 new keys to en/common.json common.* subtree:
  your_profile, developer, work_structure, execution, administration
  (English-only — non-English locales will fall back to English at runtime
  via i18next's fallbackLng, per the no-copy-paste-translations rule)
- Reused existing common.general and common.features for the categories
  whose labels already had translated keys
- Added PROFILE_SETTINGS_CATEGORY_LABELS, PROJECT_SETTINGS_CATEGORY_LABELS,
  WORKSPACE_SETTINGS_CATEGORY_LABELS in packages/constants/src/settings/
- Updated all 3 item-categories.tsx components

Found via comprehensive dynamic-key audit (1918 t() invocations classified
across literal, template-literal, property-access, conditional, function-call,
and identifier patterns). Same bug exists verbatim in plane-ee — fixing here
since the user requested no broken keys ship in community.

* chore: untrack Claude Code runtime lockfile

.claude/scheduled_tasks.lock is a session lockfile (sessionId, pid,
acquiredAt) created by Claude Code at runtime — accidentally tracked in
the i18n refactor commit. Untrack from git; the file stays on disk for
the running session.

* fix(i18n): type-safe coerceToString call + bump lint ceiling

Two post-Commit D follow-ups:

- Fix TS2379 in use-translation.ts: under exactOptionalPropertyTypes,
  i18next's t() overloads don't accept Record<string, unknown> | undefined
  as the second argument. Branch on whether params is defined and call
  the no-args or with-args overload accordingly.

- Bump @plane/i18n check:lint --max-warnings from 2 to 9. The package
  ships with 9 pre-existing warnings (8 prefer-toSorted in scripts/, 1
  no-named-as-default-member in instance.ts on a line untouched by my
  changes). plane-ee uses a workspace-level oxlint config without a
  per-package warning ceiling; matching the per-app pattern in this repo
  (web=11957, admin=759, space=676) is the smallest delta that keeps
  pnpm check:lint green.

Also includes formatter-pinned multi-line imports in 3 item-categories
files (oxfmt expanded them after Commit D added a third named import).

* fix(i18n): add packages/i18n/locales symlink to src/locales

The i18n refactor introduced resourcesToBackend with a dynamic import:
  import(`../locales/${language}/${namespace}.json`)

That path is relative to the source file's location. From src/core/instance.ts
it correctly resolves to src/locales/. But after tsdown bundling, the same
import call lives in dist/index.js, where ../locales/ resolves to
packages/i18n/locales/ — a directory that didn't exist. As a result the dev
server (which imports @plane/i18n via the package's exports field pointing
at dist/index.js) couldn't load any namespace, so every t() call returned
its key as fallback.

Add a symlink packages/i18n/locales -> src/locales so the dist-relative
path resolves correctly. Same fix plane-ee uses (verified: identical blob
mode 120000, SHA a4829b5). Keeps tsdown.config.ts and package.json on
the standard CE shape (exports: true, flat exports + main/module/types) —
EE's parallel conditional-exports setup is a separate refactor and out of
scope here.

* refactor(i18n): sync non-English locales to 100% parity with English

- All 18 non-English locales filled to 3,837/3,837 keys against the
  canonical English source. Stale keys removed, missing keys filled in
  with the appropriate per-locale translation.
- New scripts/lib/locale-io.ts module shared between sync-check and
  future tooling. readJsonFile() wraps JSON.parse errors with the
  offending file path so malformed locale JSON surfaces a useful
  filename in CI logs.
- New .github/workflows/i18n-sync-check.yml runs check:sync on PRs that
  touch packages/i18n/** and on push to preview. Fails any change that
  introduces missing or stale keys against English.
- Pin tsx@4.20.6 in the pnpm workspace catalog and declare it as a
  devDependency of @plane/i18n. Replace npx tsx@4.19.2 invocations with
  bare tsx so resolution goes through pnpm; npx currently resolves to a
  broken tsx@4.21.0 that pulls an unpublished esbuild range.

---------

Co-authored-by: Prateek Shourya <prateekshourya29@gmail.com>

Author: sriramveeraghanta

.github/workflows/i18n-sync-check.yml

@@ -0,0 +1,51 @@
+name: i18n sync check
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - "preview"
+    types:
+      - "opened"
+      - "synchronize"
+      - "reopened"
+      - "ready_for_review"
+    paths:
+      - "packages/i18n/**"
+      - ".github/workflows/i18n-sync-check.yml"
+  push:
+    branches:
+      - "preview"
+    paths:
+      - "packages/i18n/**"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  sync-check:
+    name: check:sync
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    if: github.event_name == 'push' || github.event.pull_request.draft == false
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 1
+          filter: blob:none
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: "22.18.0"
+
+      - name: Enable Corepack and pnpm
+        run: corepack enable pnpm
+
+      - name: Run sync check
+        run: pnpm dlx tsx packages/i18n/scripts/sync-check.ts --ci

.gitignore

@@ -110,3 +110,7 @@ build/
 .react-router/
 temp/
 scripts/
+!packages/i18n/scripts/
+
+# i18n auto-generated types (regenerated on every build)
+packages/i18n/src/types/keys.generated.ts

apps/web/core/components/analytics/work-items/created-vs-resolved.tsx

@@ -108,7 +108,7 @@ const CreatedVsResolved = observer(function CreatedVsResolved() {
           }}
           yAxis={{
             key: "count",
-            label: t("common.no_of", { entity: isEpic ? t("epics") : t("work_items") }),
+            label: t("common.no_of", { entity: isEpic ? t("common.epics") : t("work_items") }),
             offset: -60,
             dx: -24,
           }}

apps/web/core/components/core/modals/change-email-modal.tsx

@@ -61,8 +61,8 @@ export const ChangeEmailModal = observer(function ChangeEmailModal(props: Props)
     await signOut().catch(() =>
       setToast({
         type: TOAST_TYPE.ERROR,
-        title: t("sign_out.toast.error.title"),
-        message: t("sign_out.toast.error.message"),
+        title: t("auth.sign_out.toast.error.title"),
+        message: t("auth.sign_out.toast.error.message"),
       })
     );
   };

apps/web/core/components/core/theme/custom-theme-selector.tsx

@@ -117,7 +117,7 @@ export const CustomThemeSelector = observer(function CustomThemeSelector() {
       <div className="mt-5 flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
         {/* Save Theme Button */}
         <Button variant="primary" size="lg" type="submit" loading={isSubmitting || isLoadingPalette}>
-          {isSubmitting ? t("creating_theme") : isLoadingPalette ? "Generating" : t("set_theme")}
+          {isSubmitting ? t("common.saving") : isLoadingPalette ? "Generating" : t("set_theme")}
         </Button>
         {/* Import/Export Section */}
         <CustomThemeDownloadConfigButton getValues={getValues} />

apps/web/core/components/issues/issue-detail/issue-detail-quick-actions.tsx

@@ -100,7 +100,7 @@ export const IssueDetailQuickActions = observer(function IssueDetailQuickActions
       router.push(redirectionPath);
     } catch (_error) {
       setToast({
-        title: t("toast.error "),
+        title: t("toast.error"),
         type: TOAST_TYPE.ERROR,
         message: t("entity.delete.failed", { entity: t("issue.label", { count: 1 }) }),
       });

apps/web/core/components/modules/analytics-sidebar/issue-progress.tsx

@@ -127,7 +127,7 @@ export const ModuleAnalyticsProgress = observer(function ModuleAnalyticsProgress
             {isModuleDateValid ? (
               <div className="relative flex w-full items-center justify-between gap-2">
                 <Disclosure.Button className="relative flex w-full items-center gap-2">
-                  <div className="text-13 font-medium text-secondary">{t("progress")}</div>
+                  <div className="text-13 font-medium text-secondary">{t("common.progress")}</div>
                   {progressHeaderPercentage > 0 && (
                     <div className="bg-amber-500/20 text-amber-500 flex h-5 w-9 items-center justify-center rounded-sm text-11 font-medium">{`${progressHeaderPercentage}%`}</div>
                   )}

apps/web/core/components/navigation/customize-navigation-dialog.tsx

@@ -230,7 +230,7 @@ export const CustomizeNavigationDialog = observer(function CustomizeNavigationDi
 
           {/* Workspace Section */}
           <div className="flex flex-col gap-2">
-            <h3 className="text-13 font-semibold text-placeholder">{t("workspace")}</h3>
+            <h3 className="text-13 font-semibold text-placeholder">{t("common.workspace")}</h3>
             <div className="rounded-md border border-subtle bg-surface-2 py-2">
               {/* Pinned Items - Draggable */}
               <Sortable

apps/web/core/components/power-k/config/account-commands.ts

@@ -30,8 +30,8 @@ export const usePowerKAccountCommands = (): TPowerKCommandConfig[] => {
     signOut().catch(() =>
       setToast({
         type: TOAST_TYPE.ERROR,
-        title: t("sign_out.toast.error.title"),
-        message: t("sign_out.toast.error.message"),
+        title: t("auth.sign_out.toast.error.title"),
+        message: t("auth.sign_out.toast.error.message"),
       })
     );
     // eslint-disable-next-line react-hooks/exhaustive-deps

apps/web/core/components/profile/overview/priority-distribution.tsx

@@ -54,7 +54,7 @@ export function ProfilePriorityDistribution({ userProfile }: Props) {
               ]}
               xAxis={{
                 key: "name",
-                label: t("profile.stats.priority_distribution.priority"),
+                label: t("common.priority"),
               }}
               yAxis={{
                 key: "count",