#13592: feat(ui): group cron jobs by name folders

This PR adds support for grouping cron jobs in the Web UI using the forward slash ('/') as a delimiter in the job name. This helps organize multiple jobs into logical folders, improving clarity in the dashboard. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This change updates the Cron Jobs view (`ui/src/ui/views/cron.ts`) to render jobs grouped by a prefix derived from the job name using `/` as a delimiter. Jobs are bucketed by the first path segment (e.g., `group/job`) and rendered under a group header with a count, with ungrouped jobs collected under an "Uncategorized" bucket and sorted last. The grouping is implemented entirely client-side in the UI layer by introducing `renderGroupedJobs(props)` and swapping the previous flat `props.jobs.map(...)` list render to the grouped renderer. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - The change is localized to UI rendering, is straightforward, and does not introduce clear runtime or logic errors in the reviewed diff. - No files require special attention <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->