feat: add internationalization (i18n) support

[agmmtoo]

This pull request introduces a major refactor to support full localization (i18n) for all main pages, including authentication and static content, by moving them into locale-aware routes and updating their logic to use localized dictionaries and metadata. Additionally, it updates global styles to better support the Burmese (my) language and improves font handling. Several files are removed or replaced with redirects to their new locale-aware counterparts.

Key changes include:

1. Localization and Routing Overhaul

• All primary pages (home, login, signup, forgot password, about, privacy, terms) are now under [locale] routes, ensuring content is served in the user's language. Each page fetches the appropriate dictionary and metadata, and validates the locale parameter, returning a 404 for unsupported locales. ([app/[locale]/about/page.tsxR1-R69](https://github.com/librarease/librarease-web/pull/4/files#diff-3cf1637e12640a713bc585a37db4f0fad043105a89138c11d7e00fc16e1438c0R1-R69), [app/[locale]/login/page.tsxR1-R57](https://github.com/librarease/librarease-web/pull/4/files#diff-e35ce5e673be0d78de730bba03682a66aeff2d88a93fd984367d5765ae75235eR1-R57), [app/[locale]/signup/page.tsxR1-R47](https://github.com/librarease/librarease-web/pull/4/files#diff-309e05448c1c8dae3069d1f20405a3eb862e8bcb7dad78210ec712e63539a289R1-R47), [app/[locale]/forgot-password/page.tsxR1-R62](https://github.com/librarease/librarease-web/pull/4/files#diff-01253247ebeb29f70142e00ad54c654f7ca457586f5a03c05f9bffeb84d19947R1-R62), [app/[locale]/page.tsxR1-R119](https://github.com/librarease/librarease-web/pull/4/files#diff-6fbfba030614a776ef872a9fd818b8312fecd33e7054d62bd6ba952160fa764aR1-R119), [app/[locale]/layout.tsxR1-R25](https://github.com/librarease/librarease-web/pull/4/files#diff-44ca66e460fac15e804a2ab56f6038ef2dd0a231881294f0a3895f9ad7624c58R1-R25), [app/[locale]/privacy/page.tsxL1-R53](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL1-R53), [app/[locale]/terms/page.tsxL1-R50](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L1-R50))

• The root layout.tsx now determines the user's locale from request headers and sets the HTML lang attribute accordingly, defaulting to English if not present or invalid. ([[1]](https://github.com/librarease/librarease-web/pull/4/files#diff-eca96d2c09f31517696a26e1d0be4070e1fbab02831481bed006e275741d030bR10-R16), [[2]](https://github.com/librarease/librarease-web/pull/4/files#diff-eca96d2c09f31517696a26e1d0be4070e1fbab02831481bed006e275741d030bL63-R76))

2. Authentication Page Refactoring

• Old non-localized auth pages (/login, /signup, /forgot-password) are replaced with redirect components that forward users to their /en/ equivalents, ensuring all authentication flows are now localized. ([[1]](https://github.com/librarease/librarease-web/pull/4/files#diff-87bb40e63a4105a08e29f7d5602a447e94a68619080a086bc510bcac0cba6932L1-R4), [[2]](https://github.com/librarease/librarease-web/pull/4/files#diff-6573984fa57dc7e4e1fddb3716bbca8e1888c0af157bbe6db5118d8ef8e320ddL1-R4), [[3]](https://github.com/librarease/librarease-web/pull/4/files#diff-19602c9fa5f8bd13b3adb9b8ebfa6071c2c16723a8117940c22a53fc5f0091cdL1-R4))

3. Static Content Localization

• The privacy and terms pages are moved to [locale] routes, now rendering content from the localized dictionary instead of static API docs, and their navigation and headings are localized. ([app/[locale]/privacy/page.tsxL1-R53](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL1-R53), [app/[locale]/privacy/page.tsxL33-R67](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL33-R67), [app/[locale]/terms/page.tsxL1-R50](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L1-R50), [app/[locale]/terms/page.tsxL34-R67](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L34-R67))

4. Global Styles and Font Improvements

• The global CSS is updated to use the Geist font family by default and adds special font and line-height rules for Burmese (my) to improve readability and appearance for that language. ([[1]](https://github.com/librarease/librarease-web/pull/4/files#diff-79e0914d9fee5ca4432bdb002a24d700d31b5577265f4de3f90d5c292b9f1392L73-R77), [[2]](https://github.com/librarease/librarease-web/pull/4/files#diff-79e0914d9fee5ca4432bdb002a24d700d31b5577265f4de3f90d5c292b9f1392R145-R172))

5. Component and Metadata Enhancements

• All localized pages now generate metadata dynamically based on the current locale and dictionary, improving SEO and user experience for different languages. ([app/[locale]/about/page.tsxR1-R69](https://github.com/librarease/librarease-web/pull/4/files#diff-3cf1637e12640a713bc585a37db4f0fad043105a89138c11d7e00fc16e1438c0R1-R69), [app/[locale]/login/page.tsxR1-R57](https://github.com/librarease/librarease-web/pull/4/files#diff-e35ce5e673be0d78de730bba03682a66aeff2d88a93fd984367d5765ae75235eR1-R57), [app/[locale]/signup/page.tsxR1-R47](https://github.com/librarease/librarease-web/pull/4/files#diff-309e05448c1c8dae3069d1f20405a3eb862e8bcb7dad78210ec712e63539a289R1-R47), [app/[locale]/forgot-password/page.tsxR1-R62](https://github.com/librarease/librarease-web/pull/4/files#diff-01253247ebeb29f70142e00ad54c654f7ca457586f5a03c05f9bffeb84d19947R1-R62), [app/[locale]/page.tsxR1-R119](https://github.com/librarease/librarease-web/pull/4/files#diff-6fbfba030614a776ef872a9fd818b8312fecd33e7054d62bd6ba952160fa764aR1-R119))

This refactor sets the foundation for a fully multilingual user experience and ensures that all user-facing routes and content are properly localized and accessible.

References:
Localization and Routing: ([app/[locale]/about/page.tsxR1-R69](https://github.com/librarease/librarease-web/pull/4/files#diff-3cf1637e12640a713bc585a37db4f0fad043105a89138c11d7e00fc16e1438c0R1-R69), [app/[locale]/login/page.tsxR1-R57](https://github.com/librarease/librarease-web/pull/4/files#diff-e35ce5e673be0d78de730bba03682a66aeff2d88a93fd984367d5765ae75235eR1-R57), [app/[locale]/signup/page.tsxR1-R47](https://github.com/librarease/librarease-web/pull/4/files#diff-309e05448c1c8dae3069d1f20405a3eb862e8bcb7dad78210ec712e63539a289R1-R47), [app/[locale]/forgot-password/page.tsxR1-R62](https://github.com/librarease/librarease-web/pull/4/files#diff-01253247ebeb29f70142e00ad54c654f7ca457586f5a03c05f9bffeb84d19947R1-R62), [app/[locale]/page.tsxR1-R119](https://github.com/librarease/librarease-web/pull/4/files#diff-6fbfba030614a776ef872a9fd818b8312fecd33e7054d62bd6ba952160fa764aR1-R119), [app/[locale]/layout.tsxR1-R25](https://github.com/librarease/librarease-web/pull/4/files#diff-44ca66e460fac15e804a2ab56f6038ef2dd0a231881294f0a3895f9ad7624c58R1-R25), [app/[locale]/privacy/page.tsxL1-R53](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL1-R53), [app/[locale]/terms/page.tsxL1-R50](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L1-R50))
Auth Redirects: ([[1]](https://github.com/librarease/librarease-web/pull/4/files#diff-87bb40e63a4105a08e29f7d5602a447e94a68619080a086bc510bcac0cba6932L1-R4), [[2]](https://github.com/librarease/librarease-web/pull/4/files#diff-6573984fa57dc7e4e1fddb3716bbca8e1888c0af157bbe6db5118d8ef8e320ddL1-R4), [[3]](https://github.com/librarease/librarease-web/pull/4/files#diff-19602c9fa5f8bd13b3adb9b8ebfa6071c2c16723a8117940c22a53fc5f0091cdL1-R4))
Static Content Localization: ([app/[locale]/privacy/page.tsxL1-R53](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL1-R53), [app/[locale]/privacy/page.tsxL33-R67](https://github.com/librarease/librarease-web/pull/4/files#diff-1ceb52b4acf1b841c48d352a3f07e293ad938f6b8f7939a0bbc68826ac2079cbL33-R67), [app/[locale]/terms/page.tsxL1-R50](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L1-R50), [app/[locale]/terms/page.tsxL34-R67](https://github.com/librarease/librarease-web/pull/4/files#diff-3ca173940553dd2d1c7373fc44d5ec9562da8e79aeffdd80e9df5e4b06e808d7L34-R67))
Global Styles: ([[1]](https://github.com/librarease/librarease-web/pull/4/files#diff-79e0914d9fee5ca4432bdb002a24d700d31b5577265f4de3f90d5c292b9f1392L73-R77), [[2]](https://github.com/librarease/librarease-web/pull/4/files#diff-79e0914d9fee5ca4432bdb002a24d700d31b5577265f4de3f90d5c292b9f1392R145-R172))
Metadata Enhancements: ([app/[locale]/about/page.tsxR1-R69](https://github.com/librarease/librarease-web/pull/4/files#diff-3cf1637e12640a713bc585a37db4f0fad043105a89138c11d7e00fc16e1438c0R1-R69), [app/[locale]/login/page.tsxR1-R57](https://github.com/librarease/librarease-web/pull/4/files#diff-e35ce5e673be0d78de730bba03682a66aeff2d88a93fd984367d5765ae75235eR1-R57), [app/[locale]/signup/page.tsxR1-R47](https://github.com/librarease/librarease-web/pull/4/files#diff-309e05448c1c8dae3069d1f20405a3eb862e8bcb7dad78210ec712e63539a289R1-R47), [app/[locale]/forgot-password/page.tsxR1-R62](https://github.com/librarease/librarease-web/pull/4/files#diff-01253247ebeb29f70142e00ad54c654f7ca457586f5a03c05f9bffeb84d19947R1-R62), [app/[locale]/page.tsxR1-R119](https://github.com/librarease/librarease-web/pull/4/files#diff-6fbfba030614a776ef872a9fd818b8312fecd33e7054d62bd6ba952160fa764aR1-R119))