Add generic type parameters to Job class hierarchy for type-safe job arguments

[Copilot]

Jobs previously lacked compile-time type safety for their run method arguments. This PR introduces generic type parameters across the job hierarchy, enabling strongly-typed job implementations without sacrificing backward compatibility.

Changes

Base infrastructure

• Added <TArgs = unknown> generic parameter to BaseJob abstract class
• Propagated generics through SimpleJob, TransactionJob, BudgetJob, and EndpointJob with sensible defaults matching their expected signatures

Concrete implementations

• Updated all 11 job classes with specific type parameters reflecting their data requirements
• Created typed interfaces for job arguments (e.g., SetBudgetJobData, UpdateBillsBudgetLimitJobArgs)
• Eliminated unsafe type casting and replaced with compile-time generic constraints

Queue/worker compatibility

• Updated type guards in queueArgs.ts to work with generic BaseJob<unknown>
• No changes to runtime behavior; worker dispatcher continues to operate normally

Example

Before:

class SetBudgetForTransactionJob extends EndpointJob {
  async run(args: any) {
    const { transactionId, data } = args as JobData;
    // budget_id access is untyped
  }
}

After:

interface SetBudgetJobData { budget_id: string }
class SetBudgetForTransactionJob extends EndpointJob<{
  transactionId: string;
  data: SetBudgetJobData;
}> {
  async run({ transactionId, data }: { transactionId: string; data: SetBudgetJobData }) {
    // budget_id is now strongly typed—IDE autocomplete and type checking work
  }
}

All 77 tests passing.