Use in-memory KV store (JetKV) for simple job queue.
Build script generates an array of Zig modules in `src/app/jobs/` and
stores their name + run function (`run(allocator, params, logger)`).
View functions schedule jobs with arbitrary params.
Thread pool spawns a (configurable) number of workers and pops jobs from
the queue, then invokes the appropriate run function.
Latest Zmpl provides `template.renderWithLayout(other_template, data)`,
allowing a template to be renedered within another template.
Create layouts in `src/app/views/layouts/` or use
`jetzig generate layout [name]` and set `pub const layout = "name";` in
each view file.