Separate Job from Worker

[reneklacan]

Summary

Introduces Job/Worker separation — job data (the serialized payload) is now defined in a separate struct from the worker (the processing logic).

• Job trait (data) + Worker<Args> trait (processing) replace the old combined Worker trait
• JobContext replaces Context<T> — no more generic context parameter
• ContextValue::new(x) replaces Context::value(x)
• FromContext trait for injecting app state into workers (auto-derived for unit and single-field structs)
• #[oxanus(job = MyJobType)] attribute on #[derive(oxanus::Worker)] — defaults to {WorkerName}Job by convention
• Cron queue is now required at compile time — previously compiled but panicked at runtime when omitted
• Processable/BoxedProcessable removed from public API (internal only)
• job_envelope::Job struct renamed to JobData to avoid collision with the new Job trait
• Migration guide added in MIGRATION.md

Migration

0.9	0.10
Worker trait combines data + processing	Job trait (data) + Worker<Args> trait (processing)
Context<T> (generic over app context)	JobContext (no generic)
Context::value(x)	ContextValue::new(x)
#[derive(Serialize, Deserialize, oxanus::Worker)] on one struct	#[derive(Serialize, Deserialize)] on job, #[derive(oxanus::Worker)] on worker
config.register_worker::<W>()	config.register_worker::<W, J>()
storage.enqueue(queue, MyWorker { .. })	storage.enqueue(queue, MyJob { .. })

See MIGRATION.md for the full step-by-step guide.

Test plan

• All 38 unit + integration tests pass
• Clippy clean, fmt clean
• All examples updated and compile
• Benchmarks updated

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Note

High Risk
Large, breaking refactor across core scheduling/execution, macro expansion, and public APIs (enqueue, register_worker, context), with potential for subtle runtime/migration regressions despite broad test updates.

Overview
Introduces a breaking Job/Worker split: job payloads now implement a new Job trait, processing logic moves to Worker<Args>, and process receives (&Args, &JobContext) instead of &Context<T>.

Updates the runtime and registration pipeline to construct workers from app state via FromContext (new ContextValue::new wrapper), register workers as register_worker::<W, A>(), and enqueue only job structs (with job_envelope::Job renamed to JobData). Cron configuration is tightened so queue is required at compile time and cron args must deserialize from {}.

Refreshes macros, docs, examples, benches, web UI, and tests for the new API, and adds MIGRATION.md plus version bumps to 0.10.0.

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