#3401 A global argument that evaluates to swamp-namespace expression text is silently dropped, and literal() cannot pass it through

What happens

A global argument that evaluates to expression text naming a swamp namespace never reaches the method, and for a model whose method arguments merge the global arguments the run succeeds with the argument silently dropped.

Stored definition in models/command/shell/ctl-shell.yaml:

globalArguments:
  run: 'echo MSG=$MSG'
  env:
    MSG: ${{ literal('${{ inputs.version }}') }}

swamp behavior run ctl-shell execute exits 0. The Arguments box shows env as the object holding MSG = ${{ inputs.version }}, but stdout is MSG= with nothing after it: the whole env global argument was dropped.

With literal('${{ github.sha }}') in the same place, stdout is MSG=${{ github.sha }} as expected.

Reproduced on release 20261013.200158.0-sha.35be0b9d.

Why

After definition evaluation, containsSwampExpression (src/domain/expressions/swamp_namespaces.ts) reads the produced text as an unresolved swamp expression. In src/domain/models/method_execution_service.ts the merge of global arguments into method arguments skips every global argument for which it is true, and only the Proxy on context.globalArgs raises an error, on access. command/shell reads env from the merged method arguments, so it never touches the Proxy and runs without the variable.

Expected

Two separate things:

1. A run should not succeed with a global argument silently removed. design/enablers/expressions.md (the Limitation paragraph under Passing text through with literal()) documents an Unresolved expression in globalArguments.<field> error for this case.
2. literal() should be able to pass swamp-namespace text such as GitHub Actions ${{ inputs.version }} or ${{ steps.build.outputs.sha }} through a global argument. Today it cannot, in a stored definition or in a direct step. That needs the value to be recorded as coming from literal() so the persist gate in src/libswamp/models/direct_execution.ts and the method-execution guard both leave it alone.

Found while triaging swamp-club#3389, which is scoped to foreign text only.