feat(orgs): ORG_CREATE_NOTIFY_ADDR override for org-lifecycle notifications

[mikestankavich]

Problem

Org create, delete, and self-service signup notifications fan out to every active superadmin, in every environment. In preview that means the e2e org-creation firehose pages all superadmins with test-org noise — Tim got preview test-org create notes and asked "what is this?"

Change

New email.OrgNotifyOverride(): when ORG_CREATE_NOTIFY_ADDR is set, all three superadmin org-lifecycle notifications route to that single address instead of the superadmin fan-out (and the superadmin DB lookup is skipped entirely). Unset — the default, including prod — keeps the existing all-superadmins behavior byte-for-byte.

Set ORG_CREATE_NOTIFY_ADDR=<your-addr> in the preview environment and the churn goes only to you; Tim and everyone else stop getting it. Prod leaves it unset.

Touched paths

• email/resend.go — OrgNotifyOverride() helper (env read, trimmed, empty = unset)
• orgs/service.go — notifySuperadmins (covers create + delete) honors the override
• auth/auth.go — notifyTrialSignup (self-service signup) honors the override

Notes / decisions

• Scope: the single var governs all three org-lifecycle notices, not just admin-create — that's what actually silences the preview firehose (self-service signup is the high-volume path). Named per your suggestion; say the word if you'd rather it be create-only or renamed (e.g. ORG_NOTIFY_ADDR) to reflect the delete coverage.
• Behavior when unset is unchanged; no prod impact until the var is set in preview.

Tests

• email unit TestOrgNotifyOverride — unset/whitespace → nil, set/trimmed → single (no DB) ✅
• integration override cases for create, delete, and signup assert single-recipient (sent == 1 with two superadmins seeded); existing fan-out + nil-client tests still green ✅

🤖 Generated with Claude Code

[github-actions]

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