# Description of Changes
`i18next` allows this pattern for translations, which we use quite a few
times in our current translation files:
```json
{
"a": {
"b": "hello"
},
"a.b": "world"
}
```
This makes it ambiguous when selecting `a.b` which string will be
retrieved. We have seen issues in other languages in the current release
like this:
<img width="325" height="249" alt="image"
src="https://github.com/user-attachments/assets/f24a29f0-550f-49b8-b355-c5e5eb436558"
/>
because we are expecting this:
<img width="1022" height="210" alt="image"
src="https://github.com/user-attachments/assets/b6d5cdd4-96cd-4b2b-8f1a-465da8bf70c8"
/>
but the Spanish file has:
<img width="312" height="136" alt="image"
src="https://github.com/user-attachments/assets/1e13392c-8484-47d1-b0c4-19d52b3ea5eb"
/>
and no `removeDigitalSignature` key on its own.
This PR resolves all of these ambiguities in the source by restructuring
all of the keys to uniquely target either an object or a string, not
both. It also adds a test which will fail on any keys with a `.` in
their name, therefore making it impossible to add anything ambiguous.
# Description of Changes
This pull request introduces dynamic document meta tag management and
improves URL routing and tool metadata handling in the frontend. The
most significant changes are the addition of a custom hook to update
document meta tags (including OpenGraph tags) based on the selected
tool, enhancements to the tool selection context for better URL
synchronization, and enrichment of the `Tool` type and tool registry
with more metadata.
**Dynamic document meta management:**
* Added a new `useDocumentMeta` hook that updates the page's `<title>`,
description, and OpenGraph meta tags based on the currently selected
tool, and restores the original values on cleanup.
(`frontend/src/hooks/useDocumentMeta.ts`)
* Integrated `useDocumentMeta` into `HomePageContent` so the document's
meta tags dynamically reflect the selected tool's metadata, improving
SEO and social sharing. (`frontend/src/pages/HomePage.tsx`)
[[1]](diffhunk://#diff-85c26b21681286c20e97a26a4912f0b91812776c9d4d0c54aa541fded2565c7eR2-R8)
[[2]](diffhunk://#diff-85c26b21681286c20e97a26a4912f0b91812776c9d4d0c54aa541fded2565c7eR17)
[[3]](diffhunk://#diff-85c26b21681286c20e97a26a4912f0b91812776c9d4d0c54aa541fded2565c7eR28-R37)
**Tool metadata and context improvements:**
* Enhanced the `Tool` type and tool registry to include `title` and
`description` fields, which are now translated and used throughout the
UI and meta tags. (`frontend/src/types/tool.ts`,
`frontend/src/hooks/useToolManagement.tsx`)
[[1]](diffhunk://#diff-0b557df7bd27ac90cd2f925ddd8ef8096ea2decfaee9a5c12a94dc7a03c64bfaR46)
[[2]](diffhunk://#diff-57f8a6b3e75ecaec10ad445b01afe8fccc376af6f8ad4d693c68cf98e8863273L116-R118)
* Updated the `ToolWorkflowContext` to use the new `Tool` type for
`selectedTool`, replacing the previous `ToolConfiguration` type.
(`frontend/src/contexts/ToolWorkflowContext.tsx`)
[[1]](diffhunk://#diff-9b36e2c06dddbcfba6cb66fd0b303b7860f88ca8b562bb2534af1ab50390d385L6-R8)
[[2]](diffhunk://#diff-9b36e2c06dddbcfba6cb66fd0b303b7860f88ca8b562bb2534af1ab50390d385L72-R72)
**URL routing and synchronization:**
* Implemented logic in `ToolWorkflowContext` to synchronize the selected
tool with the browser URL, initialize tool selection from the URL on
load, and handle browser navigation (back/forward) for tool selection.
(`frontend/src/contexts/ToolWorkflowContext.tsx`)
---
## Checklist
### General
- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings
### Documentation
- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)
### UI Changes (if applicable)
- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)
### Testing (if applicable)
- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.
