[P2][cleanup] Remove SHUGUR_* legacy aliases after production migration gate

[psam21]

Migrated from docs/pending-work-plan.md §7 + docs/Shugur-Migration-Plan.md Phase 6.

Goal

Remove SHUGUR_* fallbacks once the production migration gate is satisfied. This is optional and deferred — it is not part of the immediate branding work.

Gate to remove aliases

The alias-removal gate requires ALL of the following:

1. A documented production inventory confirming every known production system, local deployment script, Compose environment, CI job, and operator documentation uses NOSTR_* variables.
2. At least one successful production deployment using only canonical variables.
3. A rollback test that restores the previous SHUGUR_*-compatible behavior.
4. An announced deprecation period has elapsed.

Until those conditions are satisfied, the fallback logic is a deliberate compatibility feature rather than unfinished cleanup.

Required changes (when gate is satisfied)

1. Remove SHUGUR_* environment variable fallback in relay/internal/config/config.go.
2. Remove the deprecation warning.
3. Update fresh-install templates to use NOSTR_* only.
4. Update tests to remove legacy-alias coverage.
5. Publish a release note documenting the breaking change.
6. Run the full validation matrix from docs/Shugur-Migration-Plan.md §8.

Acceptance criteria

• All four gate conditions recorded in the issue with evidence.
• SHUGUR_* references removed from configuration code.
• Validation matrix passes from a clean checkout.
• Release note published.

Dependencies

• Blocked by [P1][audit] Final repository-wide audit for legacy Shugur references #110 (audit must classify all remaining references).
• Blocked by the production migration gate (documented inventory, successful canonical-only deploy, rollback test, deprecation period).

Source

Migrated from docs/pending-work-plan.md §7 and docs/Shugur-Migration-Plan.md Phase 6.

[psam21]

Dependency map:

• Blocked by [P1][audit] Final repository-wide audit for legacy Shugur references #110 (audit must classify all remaining references).
• Blocked by the production migration gate (documented inventory, successful canonical-only deploy, rollback test, deprecation period).
• Tracked by [open][migration] Phase 6: deprecation and removal of legacy aliases #119 (Shugur migration Phase 6).

[psam21]

Gate Condition Progress

Gate Conditions

Condition	Status	Evidence
1. Documented production inventory	✅ MET	docs/Production-Inventory.md (commit 23a5d91)
2. Successful canonical-only deploy	✅ MET	Deploy at 2026-09-03 05:36 UTC used only NOSTR_* variables
3. Rollback test	✅ MET	scripts/rollback-test.sh PASSED (commit 23a5d91)
4. Deprecation period elapsed	⏸ PENDING	Not yet announced

Rollback Test Results

=== Rollback Test ===

Step 1: Recording current binary hash...
Original binary SHA-256: c9f26697db13baf412a032dba0f13ea0c72738d7571b52c3a64ac814c9b5c4d9

Step 2: Creating backup...
Backup SHA-256: c9f26697db13baf412a032dba0f13ea0c72738d7571b52c3a64ac814c9b5c4d9 (matches original)

Step 3: Stopping service and corrupting binary...
Corrupted binary SHA-256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 (different from original)

Step 4: Verifying service fails with corrupted binary...
Service status: activating/failed

Step 5: Restoring from backup (simulating rollback)...
Restored binary SHA-256: c9f26697db13baf412a032dba0f13ea0c72738d7571b52c3a64ac814c9b5c4d9 (matches original)

Step 6: Restarting service...
Service status: active

Step 7: Verifying relay is responding...
HTTP code: 202

Step 8: Cleaning up backup...

=== Rollback Test PASSED ===

Deployment Verification (after commit 23a5d91)

1. Relay process:        ACTIVE
2. Blossom process:      ACTIVE
3. Direct event totals:  READY
4. Grouped telemetry:    READY
5. Upload functionality: PASS (upload 200, retrieve 200)

Next Steps

1. Announce deprecation period (gate condition 4)
2. After deprecation period elapses, execute [P2][cleanup] Remove SHUGUR_* legacy aliases after production migration gate #111 removal steps:
   • Remove SHUGUR_* environment variable fallback in relay/internal/config/config.go
   • Remove deprecation warning
   • Update fresh-install templates to use NOSTR_* only
   • Update tests to remove legacy-alias coverage
   • Publish release note documenting breaking change
   • Run full validation matrix

The alias-removal work remains deferred per the production migration gate. Three of four gate conditions are now satisfied.