fix(migrate): pass the uniqueness argument the read result pin's shaped multiplicity takes

[devin-ai-integration]

What and why

develop does not build since #791 and #795 landed independently of each other: #795 gave shaped a fourth argument (unique, whether the usage must be written without nonunique), and #791's new read of a ReadStructuralFeatureAction result pin in activity.readFeature still calls it with three:

internal/translate/migrate/activity.go:2341:58: not enough arguments in call to shaped
	have (string, *sysmlv1.Element, bool)
	want (string, *sysmlv1.Element, bool, bool)

The result pin is written as an out parameter of the read action. A parameter implicitly subsets nothing (implicitlyUnique returns "" for a directed usage), so, as at the other two pin sites (activity.go pinDecl, behavior.go), it keeps whatever isUnique the pin declares: shaped(mult, r, true, false).

How it was verified

On this branch: go build ./..., go vet ./internal/translate/migrate, gofmt -l clean; go test -count=1 ./internal/translate/migrate ./tests/migrate pass. The full suite runs in CI.

Checklist

• make test and make lint pass locally (the affected packages; the rest is CI's)
• Tests added or updated for the change — none: the build is the gate, and the read-pin multiplicity is covered by tests/migrate from fix(migrate): declare script locals, keep read-pin multiplicity, ledger instant waits, UI stimuli and absent arguments #791
• Documentation extended where it already covers the surface — no behaviour change
• Changelog entry — none: this repairs the unreleased combination of two fragments already present
• baselines regenerated and make docs-counts run if a gate count moved — none moved
• No internal work-item labels (waves, slices, F4, K5) in the body, docs, or changelog

Link to Devin session: https://nasa-jpl-demo.devinenterprise.com/sessions/d4b4403c1dd54e0390049c64e3535b0f
Open in Devin Desktop: https://nasa-jpl-demo.devinenterprise.com/desktop/session/d4b4403c1dd54e0390049c64e3535b0f?variant=devin
Requested by: @HuiJun

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.