Dogfood mesh-lang#22 bare payload variant patterns in Hyperpush

[snowdamiz]

Context

This issue tracks the product-side dogfood work for hyperpush-org/mesh-lang#22:

• Source language issue: [Feature]: allow payload variant patterns to omit unused binders (Ok ->, Err ->) mesh-lang#22
• Requested language change: allow payload-bearing variant patterns to omit unused binders, e.g. Ok -> / Err -> instead of Ok(_) / Err(_).

Why this exists

If the language/compiler fix lands, Hyperpush should use it in real product code so the feature is proven outside isolated compiler tests.

Dogfood goal

After the mesh-lang implementation is available, update Hyperpush-owned code to use the shorter constructor-pattern form anywhere the payload is intentionally ignored.

Examples of the intended migration shape:

case result do
  Ok -> continue_flow()
  Err -> handle_failure()
end

instead of:

case result do
  Ok(_) -> continue_flow()
  Err(_) -> handle_failure()
end

Scope

• Find Hyperpush/Mesher-owned Mesh code that currently uses placeholder binders only to ignore payloads.
• Replace those sites with the new constructor-only pattern form once supported.
• Update any docs, examples, fixtures, or tests in Hyperpush that should show the dogfed syntax.
• Verify the affected product flows still build and run correctly.

Linkage

This issue is the downstream dogfood companion to:

• hyperpush-org/mesh-lang#22

When either issue is updated, keep the cross-links current so the language change and its real product adoption stay visible together.