no hostname on dashboard

[evilsocket]

no hostname on dashboard, only on tui, dns names once resolved must be shown on dashboard too. create relevant unit tests

[evilsocket]

@cursor for you

[cursor]

I've implemented the hostname visibility feature for the dashboard. Here's what was done:

Backend Changes:

• Added Hostname field to the Agent struct in database/agent.go to store the resolved DNS name
• Created a ResolveHostname function in api/utils.go with a DNSResolver interface for dependency injection, allowing proper unit testing
• Updated api/agent_get_rules.go to perform reverse DNS lookup when an agent polls for rules and store the hostname

Frontend Changes:

• Updated frontend/src/views/Agents.vue to display the hostname in parentheses next to the IP address (e.g., 192.168.1.1 (server.example.com))

Unit Tests:

• Created comprehensive tests in api/utils_test.go covering:
  • Successful hostname resolution (single/multiple hostnames)
  • Error handling (DNS errors, timeouts, network issues)
  • Trailing dot removal from DNS names
  • IPv6 address support
  • Nil resolver fallback behavior

All tests pass and the changes have been pushed to the cursor/dashboard-hostname-visibility-f594 branch.