BRANDCON: pass host env into brand concierge bootstrap()

[loganzartman]

What

Forward the milo env name (stage | prod | local) from getConfig() into the Brand Concierge web client's bootstrap() call.

window.adobe.concierge.bootstrap({
  instanceName: 'alloy',
  stylingConfigurations: getUpdatedChatUIConfig(),
  selector: `#${mountId}`,
  env: env?.name,          // <-- added
  onBeforeEventSend,
  onEvent: (event) => { bcAnalytics(event); },
});

Why

The web client is adding its own NewRelic browser monitoring and needs to route telemetry to the correct browser-app entity (stage vs prod). Rather than sniff the hostname inside the embeddable client, milo already has the authoritative env signal — so we pass it through.

Merge-order independence

The web client treats env as optional and defaults to stage when absent, so this PR and the web-client PR can merge in either order without breaking anything.

Scope / notes

• Single call site (bcBootstrap); the global-nav variant reuses it.
• Additive field only — existing bcBootstrap unit test asserts individual fields and continues to pass.
• A parallel copy exists at libs/c2/blocks/brand-concierge/bc-bootstrap.js; left untouched here since env is optional (those surfaces safely default to stage). Can follow up if desired.

🤖 Generated with Claude Code

[aem-code-sync]

Hello, I'm the AEM Code Sync Bot and I will run some actions to deploy your branch.
In case there are problems, just click the checkbox below to rerun the respective action.

• Re-sync branch

Commits

• 9628952 ✅ (latest)

[github-actions]

SNOW Change Request Transaction ID: 0000019c1ef37582-210fcd23

[narcis-radu]

Hey @loganzartman - I am requesting changes because I noticed some missing / incorrect elements:

• PR is against main, we're bypassing the normal flow. Unless this is tied to an exceptional release request, the code should go to stage first.
• PR does not provide any QA / test pages
• PR does not handle C2 blocks. I see a mention about the C2 block being left untouched, but I really want to understand whether the change is needed or not.