chore: add gitleaksignore for false positive secret detections

Add .gitleaksignore to suppress false positive secret scanning alerts for:
- Route53 hosted zone IDs (public identifiers, not secrets)
- Terraform sensitive variable declarations (not actual secret values)
- AWS account IDs (non-sensitive identifiers)
- Database connection string patterns (variable declarations, not credentials)

All actual secrets are already protected via .gitignore (*.tfvars files).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Noah Boyers

.gitleaksignore

@@ -0,0 +1,25 @@
+1d226661ce8ee8a2be953a10200f76187dd038bd:infra/aws/us-east-2/k8s/coder-server/main.tf:aws-account-id:249
+1d226661ce8ee8a2be953a10200f76187dd038bd:infra/aws/us-east-2/k8s/coder-server/main.tf:aws-account-id:249
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-east-2/vpc-peering/main.tf:terraform-sensitive-variable:33
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-east-2/vpc-peering/main.tf:terraform-sensitive-variable:27
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/acm/main.tf:terraform-sensitive-variable:22
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/acm/main.tf:terraform-sensitive-variable:10
+ac48444a685bde17f83221a9c0efb6f3fee2ebbb:infra/aws/us-east-2/acm/main.tf:terraform-sensitive-variable:10
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-east-2/route53/main.tf:terraform-sensitive-variable:14
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-east-2/route53/main.tf:terraform-sensitive-variable:66
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:67
+ac48444a685bde17f83221a9c0efb6f3fee2ebbb:infra/aws/us-east-2/terraform-backend/main.tf:terraform-sensitive-variable:10
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:route53-zone-id:40
+ac48444a685bde17f83221a9c0efb6f3fee2ebbb:infra/aws/us-east-2/terraform-backend/main.tf:terraform-sensitive-variable:16
+ac48444a685bde17f83221a9c0efb6f3fee2ebbb:infra/aws/us-east-2/terraform-backend/main.tf:terraform-sensitive-variable:22
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/k8s/coder-server/main.tf:terraform-sensitive-variable:43
+1d226661ce8ee8a2be953a10200f76187dd038bd:infra/aws/us-east-2/rds/main.tf:database-connection-string:239
+1d226661ce8ee8a2be953a10200f76187dd038bd:infra/aws/us-east-2/rds/main.tf:database-connection-string:265
+1d226661ce8ee8a2be953a10200f76187dd038bd:infra/aws/us-east-2/rds/main.tf:database-connection-string:238
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:aws-account-id:40
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:55
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:49
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:37
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:31
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-west-2/route53/main.tf:terraform-sensitive-variable:14
+8fa97fe4d1e4a477bf69361498a8801050856a3c:infra/aws/us-east-2/route53/main.tf:terraform-sensitive-variable:54