fix: support a single audience/campaign per selector in fragment manifests

[ramboz]

Problem

A fragment-level Audience Manifest (or Campaign Manifest) with a single audience/campaign per selector crashes the plugin.

parseAudienceManifest / parseCampaignManifest call audiences.forEach(...) / campaigns.forEach(...), but aggregateEntries only produces an array when a selector has multiple values — a selector with a single value leaves audience/campaign (and url) as a scalar string. String.prototype.forEach doesn't exist, so it throws audiences.forEach is not a function, which aborts loadEager and leaves the fragment un-personalized (window.hlx.audiences / .campaigns never gets set).

Every existing manifest fixture uses two audiences/campaigns per selector, so this single-value path was never exercised.

Fix

Normalize audience/campaign and url to arrays with [].concat(...) before iterating — a no-op for the existing multi-value case, correct for the single-value case.

Tests

Adds fragment-level fixtures + tests for a single audience and a single campaign per selector. They fail red before this change (waitForNamespace times out because the plugin threw) and pass after. Full audiences + campaigns suites green (46 passed), lint clean.

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Found while building a "bring your own decision engine" personalization integration, where each slot's manifest carries exactly one (remote) audience — a common shape for per-slot personalization, so it's worth handling out of the box.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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