feat: add internationalization (i18n) support

[Jefsky]

Summary

This PR implements i18n support for the page-agent UI package as requested in issue #195.

Changes Made:

1. Created JSON locale files:

   • • English translations (base language)
   • • Chinese translations

2. **Refactored **:

   • Now imports from JSON locale files instead of having inline objects
   • TypeScript types are inferred from the English JSON schema
   • Maintains the same TranslationKey and TranslationParams types

3. **Updated **:

   • Added compiler option
   • Included in the include patterns

Architecture:

The i18n system already existed in the codebase (I18n class with locale support for 'en-US' and 'zh-CN'). This PR simply externalizes the translation data into JSON files for easier maintenance and future translation contributions.

Testing:

• TypeScript compilation: PASSED
• Library build: PASSED (

root@1.8.1 build:libs
node scripts/build-libs.js

✔ @page-agent/page-controller

@page-agent/page-controller@1.8.1 build
vite build

(node:62494) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36m📦 Building @page-agent/page-controller�[39m
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 11 modules transformed.
rendering chunks...
�[32m
�[36m[unplugin:dts]�[32m Start generate declaration files...�[39m
computing gzip size...
�[2mdist/lib/�[22m�[36mSimulatorMask-BfJiQVCo.js �[39m�[1m�[2m11.60 kB�[22m�[1m�[22m�[2m │ gzip: 3.23 kB�[22m�[2m │ map: 15.64 kB�[22m
�[2mdist/lib/�[22m�[36mpage-controller.js �[39m�[1m�[2m75.11 kB�[22m�[1m�[22m�[2m │ gzip: 16.09 kB�[22m�[2m │ map: 157.83 kB�[22m
�[32m�[36m[unplugin:dts]�[32m Start bundling declaration files...�[39m
Analysis will use the bundled TypeScript version 6.0.3
�[32m�[36m[unplugin:dts]�[32m Declaration files built in 1891ms.
�[39m
�[32m✓ built in 2.14s�[39m

✔ @page-agent/ui

@page-agent/ui@1.8.1 build
vite build

(node:62516) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36m📦 Building @page-agent/ui�[39m
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 9 modules transformed.
rendering chunks...
�[32m
�[36m[unplugin:dts]�[32m Start generate declaration files...�[39m
computing gzip size...
�[2mdist/lib/�[22m�[36mpage-agent-ui.js �[39m�[1m�[2m37.39 kB�[22m�[1m�[22m�[2m │ gzip: 9.77 kB�[22m�[2m │ map: 37.19 kB�[22m
�[32m�[36m[unplugin:dts]�[32m Start bundling declaration files...�[39m
Analysis will use the bundled TypeScript version 6.0.3
�[32m�[36m[unplugin:dts]�[32m Declaration files built in 1798ms.
�[39m
�[32m✓ built in 1.98s�[39m

✔ @page-agent/llms

@page-agent/llms@1.8.1 build
vite build

(node:62483) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36m📦 Building @page-agent/llms�[39m
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 5 modules transformed.
rendering chunks...
�[32m
�[36m[unplugin:dts]�[32m Start generate declaration files...�[39m
computing gzip size...
�[2mdist/lib/�[22m�[36mpage-agent-llms.js �[39m�[1m�[2m13.77 kB�[22m�[1m�[22m�[2m │ gzip: 3.83 kB�[22m�[2m │ map: 26.20 kB�[22m
�[32m�[36m[unplugin:dts]�[32m Start bundling declaration files...�[39m
Analysis will use the bundled TypeScript version 6.0.3
�[32m�[36m[unplugin:dts]�[32m Declaration files built in 1716ms.
�[39m
�[32m✓ built in 1.80s�[39m

✔ @page-agent/core

@page-agent/core@1.8.1 build
vite build

(node:62517) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 5 modules transformed.
rendering chunks...
�[32m
�[36m[unplugin:dts]�[32m Start generate declaration files...�[39m
computing gzip size...
�[2mdist/esm/�[22m�[36mpage-agent-core.js �[39m�[1m�[2m36.34 kB�[22m�[1m�[22m�[2m │ gzip: 11.10 kB�[22m�[2m │ map: 62.76 kB�[22m
�[32m�[36m[unplugin:dts]�[32m Start bundling declaration files...�[39m
Analysis will use the bundled TypeScript version 6.0.3
�[32m�[36m[unplugin:dts]�[32m Declaration files built in 2308ms.
�[39m
�[32m✓ built in 2.42s�[39m

✔ page-agent

page-agent@1.8.1 build
vite build && npm run build:demo

(node:62515) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 1 modules transformed.
rendering chunks...
�[32m
�[36m[unplugin:dts]�[32m Start generate declaration files...�[39m
computing gzip size...
�[2mdist/esm/�[22m�[36mpage-agent.js �[39m�[1m�[2m0.61 kB�[22m�[1m�[22m�[2m │ gzip: 0.29 kB�[22m�[2m │ map: 1.26 kB�[22m
�[32m�[36m[unplugin:dts]�[32m Start bundling declaration files...�[39m
Analysis will use the bundled TypeScript version 6.0.3
�[32m�[36m[unplugin:dts]�[32m Declaration files built in 2636ms.
�[39m
�[32m✓ built in 2.74s�[39m

page-agent@1.8.1 build:demo
vite build --config vite.iife.config.js

(node:62564) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
(Use node --trace-warnings ... to show where the warning was created)
�[36mvite v7.3.2 �[32mbuilding client environment for production...�[36m�[39m
transforming...
�[32m✓�[39m 114 modules transformed.
rendering chunks...
computing gzip size...
�[2mdist/iife/�[22m�[36mpage-agent.demo.js �[39m�[1m�[2m204.56 kB�[22m�[1m�[22m�[2m │ gzip: 57.26 kB�[22m
�[32m✓ built in 320ms�[39m

✔ All 5 tasks completed )

Benefits:

• Easier for translators to work with JSON files
• Translation workflow can be integrated with external tools (Crowdin, Weblate, etc.)
• Clear separation between code and translations

[CLAassistant]

All committers have signed the CLA.

[gaomeng1900]

Could you explain the expected benefit of this change?

[Jefsky]

The key benefits of this change are:

1. Separation of concerns — Translation data is decoupled from code, making it easier for translators to work with JSON files without touching the codebase
2. External tooling integration — JSON files can be fed into translation management systems like Crowdin, Weblate, or GitLok, enabling professional translation workflows
3. Easier maintenance — Adding or updating translations no longer requires code changes or recompilation
4. Scalability — New language contributions become straightforward (just add a new JSON file following the existing schema)

The existing i18n infrastructure (I18n class with locale support) was already in place — this PR just externalized the inline translation objects into JSON files.