Add settings UI to allow groups or projects to opt in to web-based commit signing
## Context
We need a UI in the Settings area that allows users to opt-in to web-based commit signing at both the Group (cascading down to sub groups and projects) and project level.
## Problem Statement
The "Sign web-based commits" setting does not logically fit in any of the existing sections:
- `Branch rules` and `Settings > Merge requests` are not appropriate fits
- `Settings > General > Visibility, project features, permissions` is disjointed from the centralized `Settings > Repository` page
## Scope: Short-term Solution
This issue will implement a **short-term design solution** by creating a new `Settings > Repository > General` bucket to house the "Sign web-based commits" setting.
## Design Approach
Create a new `Settings > Repository > General` section that will:
- Serve as a logical home for the "Sign web-based commits" setting
- Provide a scalable foundation for future repository-related settings
- Maintain consistency with the centralized repository settings structure
## UI Text
**Option 1 (Simpler):**
```
☐ Sign web-based commits
Automatically sign commits made through the web interface.
```
**Option 2 (With signature key context):**
```
☐ Sign web-based commits
Automatically sign commits made through the web interface with the instance's signing key.
```
## Objectives
1. **Create `Settings > Repository > General` section**: Implement new UI section in the Repository settings page
2. **Implement "Sign web-based commits" toggle**: Add the setting to allow opt-in at project level
3. **Support group-level cascading**: Ensure the setting can cascade from group to sub-groups and projects
4. **Update documentation**: Document the new setting location and functionality
## Acceptance Criteria
- [ ] `Settings > Repository > General` section created and visible in the UI
- [ ] "Sign web-based commits" toggle implemented and functional at project level
- [ ] Group-level setting with cascading behavior implemented
- [ ] Documentation updated with new setting location
- [ ] Design reviewed and approved by stakeholders
## Future Considerations
A long-term assessment should be conducted to evaluate whether centralizing all repository settings from `Settings > General > Visibility, project features, permissions` into `Settings > Repository` would improve the overall user experience.
issue