fix: workflow deploy nil svc error

[Cynthia-0203]

What this PR does / Why we need it:

Fixes a panic when creating a workflow task for Helm services with values auto-sync enabled, where the selected service has not been deployed to the target environment yet.

Previously, the deploy job assumed the service already existed in the environment and accessed its render data directly during auto-sync. For first-time deployments, the environment service does not exist yet, causing a nil pointer panic and a 500 response.

This PR allows first-time Helm service deployments to proceed with the submitted values, while preserving source metadata after deployment so future auto-sync runs can fetch the latest values correctly.

What is changed and how it works?

If the service is not deployed yet, sync the latest values from the template service's helm source so the deploy is not driven by empty/stale user input. A new ValuesSyncedFromSource flag on JobTaskHelmDeploySpec records that the values came from source. At deploy time, for a newly deployed service whose values were synced from source, the new render's AutoSyncYaml is seeded with the pure source values so future auto-sync runs compare against a clean baseline. If the template service has no source configured, it falls back to the submitted values — no regression.

Does this PR introduce a user-facing change?

• API change
• database schema change
• upgrade assistant change
• change in non-functional attributes such as efficiency or availability
• fix of a previous issue

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