Remove the redundant CiphernodeHandle constructor #1699

What was difficult to maintain

CiphernodeHandle had a ten-argument constructor whose only job was to assign each argument to the matching struct field. Several arguments had the same or similar types, so call sites depended on positional ordering and were harder to review safely.

When it matters

This comes up whenever the ciphernode builder gains, removes, or reorders a runtime handle such as the event bus, network interface, event store, or aggregate IDs. A positional constructor makes an otherwise small builder change touch two definitions and makes swapped values less obvious during review.

What changed

The redundant constructor was removed and the builder now constructs CiphernodeHandle with named fields at the single call site.

Why this is simpler

Each value is visibly paired with its destination field, adding a field requires changing only the struct literal, and 26 lines of forwarding code are gone without changing runtime behavior.

Checks

The locked workspace build, strict Clippy run, formatting checks, and pre-push lint suite pass.