Neeraj Fix Chart Rendering Issue and Dark Mode Legend

[Neeraj-Kondaveeti]

Description

INITIAL TASK DESCRIPTION:

CHANGES REQUESTED:

Related PRS (if any):

This frontend PR is related to the Development Backend PR.

This PR is hotfix for #4896

Main changes explained:

• Fixed an issue where the Hiring Analytics chart was not rendering.
• Updated API filter handling to allow fetching all roles when no roles are selected.
• Fixed dark mode legend display by replacing text-based indicators with styled color blocks to correctly match chart bars.

How to test:

1. check into current branch
2. do npm install and ... to run this PR locally
3. Clear site data/cache
4. log as admin user
5. Navigate to: http://localhost:5173/applicant-volunteer-ratio
6. Verify:
   • Chart loads correctly and does not get stuck on "Loading..."
7. Toggle dark mode:
   • Legend colors should match chart bars (blue for Total Applications, green for People Hired)
   • Legend should be clearly visible and readable

Screenshots or videos of changes:

Note:

• This PR specifically addresses post-merge feedback related to chart rendering and dark mode legend visibility

[netlify]

✅ Deploy Preview for highestgoodnetwork-dev ready!

Name	Link
🔨 Latest commit	0fe1ea1
🔍 Latest deploy log	https://app.netlify.com/projects/highestgoodnetwork-dev/deploys/69d72bcaaa91fd000818aad3
😎 Deploy Preview	https://deploy-preview-5123--highestgoodnetwork-dev.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rajanidi1999]

working as expected and im approving the PR