feat: add dashboard-api support to AWS provider

[ya-luotao]

Summary

• Wire up the dashboard-api Nomad job for the AWS provider (ECR repo already existed but the job was never deployed)
• Refactor job-dashboard-api module to use logs_collector_address (string) instead of logs_proxy_port (object), matching every other job module in the codebase
• Document DASHBOARD_API_COUNT in self-host.md for both GCP and AWS

Details

The dashboard-api ECR repository was created in iac/provider-aws/init/repositories.tf but the Nomad job module was never instantiated in the AWS provider. This PR adds the full wiring:

File	Change
iac/modules/job-dashboard-api/variables.tf	Replace logs_proxy_port object with logs_collector_address string
iac/modules/job-dashboard-api/main.tf	Use logs_collector_address directly
iac/provider-gcp/nomad/main.tf	Update GCP caller to match the new module interface
iac/provider-aws/init/outputs.tf	Export dashboard_api_repository_name
iac/provider-aws/variables.tf	Add dashboard_api_count (default 0)
iac/provider-aws/Makefile	Add DASHBOARD_API_COUNT tfvar
iac/provider-aws/main.tf	Pass dashboard vars to nomad module
iac/provider-aws/nomad/variables.tf	Add dashboard variables
iac/provider-aws/nomad/main.tf	Add module "dashboard_api" block
self-host.md	Document optional dashboard-api for both providers

Disabled by default (DASHBOARD_API_COUNT=0). Traefik routes dashboard-api.<domain> via Consul catalog service tags at priority 1000. No ALB or DNS changes needed (wildcard DNS already covers it).

Test plan

• terraform fmt -check passes
• terraform validate passes
• Deployed on AWS with DASHBOARD_API_COUNT=1
• Nomad job starts and registers in Consul
• Traefik picks up service and routes dashboard-api.<domain> correctly
• curl https://dashboard-api.<domain>/health returns {"message":"Health check successful"}
• Verify GCP provider still plans cleanly with the logs_collector_address refactor

🤖 Generated with Claude Code

[sitole]

Hi, thank you for your contribution. We decided we don't want to support the dashboard API, as it's a non-critical part used only for our enterprise deployment and not needed for self-hosting. Thank you for understanding that.