feat: read-only service logs endpoint for all services including core

[yasinBursali]

Problem

• The existing /v1/extension/logs endpoint returns 403 for core services (llama-server, open-webui, dashboard-api, dashboard)
• Users cannot view logs for core services through the dashboard
• Container name resolution is hardcoded as dream-{service_id} which fails for open-webui (container is dream-webui)

Proposed Solution

• Add POST /v1/service/logs endpoint that works for ALL services (core + extensions)
• Use Docker Compose label lookup (com.docker.compose.service) for accurate container name resolution
• Keep existing /v1/extension/logs unchanged for backwards compatibility

Scope

• bin/dream-host-agent.py only — host agent endpoint

[yasinBursali]

Implementation PR: #806

[yasinBursali]

Closing — issue filed on wrong repo.