fix(instance): handle stale DB records after restart + prevent Redis connection spam

[devin-ai-integration]

📋 Description

Fixes two critical issues that affect deployments on PaaS platforms (Render, Railway, etc.) where the server restarts frequently:

1. Stale Instance Deadlock After Restart

When Evolution API restarts, the in-memory waInstances map is cleared but database records persist. This creates a deadlock:

• DELETE instance → 404 (not in memory, guard blocks it)
• CREATE instance → 403 "name already in use" (DB record still exists)
• SET WEBHOOK → 500 "Cannot read instanceId" (instance not in memory)
• CONNECT → 404 (instance never loaded)
• Result: clients like BotWave cannot pair or reconnect after any restart

Fix: The instanceLoggedGuard now detects when an instance exists in the database but NOT in memory (stale after restart). Instead of returning 403, it auto-cleans the stale DB record via cleaningStoreData() and allows re-creation.

2. Redis Connection Spam When Disabled

The Redis client (rediscache.client.ts) would attempt to connect regardless of CACHE_REDIS_ENABLED setting. Since the Dockerfile copies .env.example as .env (which had CACHE_REDIS_ENABLED=true), deployments without Redis got flooded with "redis disconnected" errors every second.

Fix:

• Redis client now checks ENABLED flag and URI before attempting connection
• .env.example defaults changed to CACHE_REDIS_ENABLED=false and CACHE_LOCAL_ENABLED=true so deployments without Redis work out of the box

🔗 Related Issue

Fixes instance creation failures and Redis spam on PaaS deployments (Render free tier).

🧪 Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)

🧪 Testing

• Manual testing completed
• Functionality verified in development environment
• No breaking changes introduced
• npm run build passes
• npm run lint:check passes

Files Changed

• src/api/guards/instance.guard.ts — Added stale instance detection and cleanup
• src/cache/rediscache.client.ts — Added ENABLED/URI checks before connecting
• .env.example — Changed Redis default to false, local cache to true

✅ Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have manually tested my changes thoroughly
• I have verified the changes work with different scenarios

📝 Additional Notes

This is the third in a series of PaaS deployment fixes:

• PR fix(deploy): map DATABASE_URL to DATABASE_CONNECTION_URI for PaaS deployments #1: DATABASE_URL → DATABASE_CONNECTION_URI mapping
• PR feat(server): add keep-alive ping to prevent PaaS services from sleeping #2: Keep-alive ping to prevent Render sleep
• PR fix(instance): handle stale DB records after restart + prevent Redis connection spam #3 (this): Stale instance cleanup + Redis guard

Link to Devin session: https://app.devin.ai/sessions/812442be799c4cd59ca9c40eee75263b
Requested by: @eksucampusmarketplace-cell

[devin-ai-integration]

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