Fix build: tag the Link_Workflow parse warning

[stephanos]

main is currently broken

common/nexus/links.go:50:6: undefined: fmt

go build ./common/nexus/ fails on origin/main as of fc7b395.

Cause

A semantic merge conflict between two PRs that merged around the same time:

• Make Nexus link warnings aggregatable #11685 removed the fmt import from links.go, having replaced all three fmt.Sprintf message interpolations with log tags.
• [SDK Ergonomics] NEXUS-519: Support Query-backed Nexus Operations #11274 added a new Link_Workflow case that logs via fmt.Sprintf.

Neither diff touched the other's lines, so git merged both cleanly and the result does not compile.

Fix

Convert the new case to the same static-message-plus-tags form as the other three, rather than re-adding the import — that keeps the warning aggregatable in Loki, which is what #11685 was for.

Testing

go build ./..., go test -tags test_dep ./common/nexus/, gofmt. No remaining fmt. references in the file.

🤖 Generated with Claude Code

[github-actions]

Claude finished @stephanos's task in 1m 16s —— View job

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Reviewed 1 file, 1 finding.
• stephanos/fix-links-fmt-merge

[github-actions]

nit — This is now the third byte-identical logger.Warn block in one function; worth collapsing.

After #11685 made the message static, the three failure branches differ only in which converter they call — the warn call itself is the same six lines repeated. The nexus-link-type tag already carries everything the reader needs to tell them apart, so the duplication buys nothing.

Fine to leave for the build fix and do separately; flagging since this PR creates the third copy.

Suggestion: Pick the converter in the switch, then convert and log once after it:

var convert func(nexus.Link) (proto.Message, error)  // or a small variant-wrapping closure
switch nexusLink.Type {
case ...WorkflowEvent: ...
}
if err != nil {
    logger.Warn("failed to parse Nexus link", tag.Error(err),
        tag.NewStringTag("nexus-link-type", nexusLink.Type), tag.URL(nexusLink.URL.String()))
    continue
}