docs: document CONNECTOR_DISCOVERY_ENABLED for Fusion-only / air-gapped deployments

[antoniocali]

Summary

Companion to datazip-inc/olake-ui#382, which adds a CONNECTOR_DISCOVERY_ENABLED server flag (and a matching DEFAULT_CONNECTOR_VERSION) to skip Docker Hub / ECR / GCR queries in Fusion-only and air-gapped deployments (datazip-inc/olake-ui#380).

The chart needs no template change to support this — olakeUI.env is already a passthrough map, so any env var set there is propagated to the UI pod. This PR is purely about discoverability: putting the new knob where operators will actually see it.

Changes

• helm/olake/values.yaml — add a commented example under olakeUI.env showing how to disable discovery and pin a default version.
• helm/olake/README.md — add a "Disabling Connector Discovery (Fusion-only / Air-gapped)" subsection alongside the existing "Private Container Registry" section. Explains the use case (Fusion-only Iceberg maintenance, no CDC) and the registry-rate-limit motivation.

Notes

• Dependent on feat(server): add CONNECTOR_DISCOVERY_ENABLED flag to disable registry polling olake-ui#382 actually merging — the flag in the docs is a no-op against the current olakego/ui:latest. Suggest merging this after, or after a new UI image is tagged.
• No behavior change for any existing deployment; chart templates and defaults are untouched.

Test plan

• helm lint helm/olake/ clean
• Manual: render with helm template ... --set olakeUI.env.CONNECTOR_DISCOVERY_ENABLED=false --set olakeUI.env.DEFAULT_CONNECTOR_VERSION=v0.3.18 and confirm both vars appear in the olake-ui Deployment env (they should, since olakeUI.env is already passed through via the existing range loop)

[schitizsharma]

Hi @antoniocali could you please take a pull from the latest staging branch to fix the vulnerabilities.

Is this feature urgent? We are discussing internally to fix this on both worker and ui side currently.

[antoniocali]

Hi @antoniocali could you please take a pull from the latest staging branch to fix the vulnerabilities.

Is this feature urgent? We are discussing internally to fix this on both worker and ui side currently.

Not urgent
Things works, just create a lot of noise

Let me anyway merge from staging and push to resolve conflicts

[antoniocali]

Hi @antoniocali could you please take a pull from the latest staging branch to fix the vulnerabilities.

Is this feature urgent? We are discussing internally to fix this on both worker and ui side currently.

Just to also check, this PRs would make sense on helm only after datazip-inc/olake-ui#382 is closed, since that's where the change for connector-discovery-flag is implemented.