feat(recruitment): enhance recruitment dashboard with advanced analytics charts

[iamkhanraheel]

Summary

Adds four custom analytics charts to the Recruitment dashboard, replacing charts that were less actionable (Job Applicant Source, Job Offer Status, Interview Status).

New charts:

• Recruitment Funnel - 6-stage bar chart (Applied → Shortlisted → Interviewed → Offered → Accepted → Rejected); Applied/Shortlisted from Job Applicant, Interviewed from Interview, Offered/Accepted/Rejected from Job Offer status
• Source to Hire Conversion - compares total applicants vs hired per source; hired = Job Offer accepted

• Open Position Age - shows top 10 oldest open positions by days since posting
• Interviewer Load - pending vs total interviews per interviewer (top 10 by load)

All charts support company-level filtering and use Custom chart type for cross-doctype aggregation.

Also updates Job Applicant Pipeline to Pie chart with a cap of 8 groups.

[greptile-apps]

Confidence Score: 4/5

The PR is not safe to merge until progressed applicants remain represented in the Shortlisted funnel stage.

The funnel still derives Shortlisted exclusively from the applicant’s current status, while later workflow transitions overwrite that status and leave the chart undercounting progressed candidates.

Files Needing Attention: hrms/hr/dashboard_chart_source/recruitment_funnel/recruitment_funnel.py

_{Reviews (2): Last reviewed commit: "fix: company filter scoping and rewrite ..." | Re-trigger Greptile}

[greptile-apps]

Shortlisted stage loses progressed applicants

When a shortlisted applicant advances, the Interview or Job Offer workflow overwrites their status with Accepted or Rejected, so this current-status check drops them while later stages still count their records, causing the funnel to underreport Shortlisted and potentially show it below later stages.

Knowledge Base Used: Recruitment Pipeline: Requisition to Job Offer