Connect Kibana via HTTP with basic auth credentials

[Copilot]

Kibana connectivity was previously checked via raw TCP only, with no way to supply credentials. This adds HTTP-based checking against Kibana's /api/status endpoint with Basic Auth support.

Config structure change

kibana in config.yml moves from a flat address list to a structured block:

# Before
kibana:
  - 10.0.1.26:5601

# After
kibana:
  addresses:
    - 10.0.1.26:5601
  username: elastic
  password: changeme

Code changes

• config/config.go — introduces KibanaConfig (addresses + credentials) and AppConfig which embeds it alongside an inline map[string][]string for all other TCP services
• checker/checker.go — adds CheckKibanaConnection which GETs http://<addr>/api/status, sets Authorization: Basic … when both credentials are present, and treats HTTP ≥ 400 as failure
• main.go — dispatches Kibana addresses to CheckKibanaConnection; all other services continue using the TCP checker
• config.yml / docker/config.yml — updated to the new Kibana block format

[alanthssss]

LGTM