[P2] Driver facturador (Java wrapper, contained)

[Railly]

Context

SUNAT's official "Facturador" is a Java app. PR #1's recon dossier (src/commands/cpe/RESEARCH.md) shaped a driver that wraps a containerized version of it.

Scope

• src/cpe/drivers/facturador.ts — implement CpeDriver by talking HTTP to a sibling Java Facturador container
• doctor() checks: container reachable, Java 8u202 running, cert mounted
• Settle the API shape (single HTTP endpoint vs file-based DATA/IN folder)

Why P2

Once the drivers nubefact/apisperu (#12) cover the "I already pay an OSE" case, the Facturador driver is for empresas that want to run SUNAT's free Java tool without paying an OSE. Nice but not urgent.

Blocked on

• API shape decision (HTTP wrapper or DATA folder convention)
• Whether to bundle Docker compose for the Java container

References

• src/commands/cpe/RESEARCH.md — original recon
• LIMITATIONS.md → "Drivers facturador, nubefact, apisperu" line