#3826 method run masks a sensitive array from --input element by element, exposing its shape (regression from #3752)

What happens

swamp model method run --json masks a sensitive array argument passed with --input element by element. Before swamp-club#3752 the whole value was masked.

A method argument declared as command: z.array(z.string()).meta({ sensitive: true }), run with:

swamp model method run sa exec --input '{"name":"visible-name","command":["curl","-H","Bearer <token>"]}' --json

now reports:

"methodArguments": { "name": "visible-name", "command": ["***", "***", "***"] }

Expected (swamp-club#3555, and what the UAT asserts):

"methodArguments": { "name": "visible-name", "command": "***" }

The token itself is not printed. But the output now shows the array's length and shape, which come from the operator's --input, not from the definition.

Why this looks unintended

#3752 (swamp PR #3309, da8bacdf) moved the completed event and method-summary report onto the cache's masking walk. Its notes say that only a sensitive container whose keys are the definition's own authored text is now masked leaf by leaf, and that "a container whose keys came from data is still masked whole". Since #3749, an --input value is the run's data. So an array typed through --input should still be masked whole, and it isn't. Either arrays from --input slip past the "came from data" check, or #3752 changed #3555's contract without saying so for this case.

Evidence

• UAT: tests/cli/adversarial/sensitive_literal_args_test.ts, "swamp model method run masks a sensitive method argument passed with --input or --stdin as *** in --json methodArguments".
• The last green scheduled adversarial Tier 6 run on swamp-uat main was 2026-10-22 18:13 UTC. It has failed on this test ever since, on stables 20261023.022020.0-sha.7bbeadcf, 20261023.012247.0-sha.06b63974 and 20261023.123914.0-sha.8540c1e3.
• Release UAT doesn't run the adversarial tiers, so this reached stable without failing a release gate.
• Not fixed on swamp main as of 45393d82.

Ask

Mask an array (or any container) that came from --input / --stdin whole in the completed event, the method-summary report and --json output, as #3555 specified. If per-element masking is intended, say so here, and swamp-uat will update the test.