Add internal environment to deploy workflow

[ofahimIQSS]

Summary
This change updates .github/workflows/deploy.yml to let us deploy the SPA to our internal environment in addition to qa, beta, and demo.

What changed
Added internal to workflow_dispatch.inputs.environment.options so it shows up in the manual run menu.
Added .env creation step gated by if: github.event.inputs.environment == 'internal'.
Added SCP step to copy the built WAR to the internal host.
Added SSH step to run the Payara deploy on the internal host.

Follow-ups (blocking deploy)
Create the internal environment (or repo-level) secrets used by these new steps:
INTERNAL_DATAVERSE_BACKEND_URL
INTERNAL_OIDC_CLIENT_ID
INTERNAL_OIDC_AUTHORIZATION_ENDPOINT
INTERNAL_OIDC_TOKEN_ENDPOINT
INTERNAL_OIDC_LOGOUT_ENDPOINT
INTERNAL_OIDC_STORAGE_KEY_PREFIX
INTERNAL_PAYARA_INSTANCE_HOST
INTERNAL_PAYARA_INSTANCE_USERNAME
INTERNAL_PAYARA_INSTANCE_SSH_PRIVATE_KEY

Acceptance criteria
Workflow “Run workflow” menu shows internal.
Manual run with environment=internal completes successfully.
SPA is served from the internal host at the expected base path and login works.

[coveralls]

coverage: 98.05% (+0.8%) from 97.207%
when pulling fc31a89 on Internal-update-deploy.yml
into cd0b794 on develop.