fix: replace single-IP ping with multi-method internet check

[fe51]

Pitch

ICMP ping to public IPs (1.1.1.1, 8.8.8.8) can be blocked on mobile/4G networks even when real internet access works. This caused false-positive internet failures on some watchdog CRON run

Modifications

Replaces ping_host(INTERNET_IP) with internet_check_ok() which tries lightweight HTTP/HTTPS probes first (generate_204 endpoints) and falls back to pinging multiple IPs only if all HTTP checks fail. No new dependencies — uses stdlib urllib.request.

---

Hypothesis

ICMP — Internet Control Message Protocol is a low-level network protocol used for diagnostics (ping, traceroute, "host unreachable" messages). It operates below TCP/UDP — no ports, just raw IP packets with a type field.

Why operators might block it:

• DDoS mitigation — ICMP flood attacks are trivial to launch, so many carriers simply drop inbound/outbound ICMP at their edge to protect infrastructure.
• Traffic prioritization — on constrained 4G links, operators deprioritize or discard "non-revenue" control traffic; ICMP is the easiest thing to drop without breaking real applications.
• Firewalling policy — some operators run CGNAT + stateful firewalls that only track TCP/UDP sessions; ICMP has no session concept so it gets dropped by default.
• Prevent network mapping — blocking ICMP makes it harder for outsiders to probe the operator's internal topology.

HTTP/HTTPS traffic on port 443 is virtually never blocked because that would break the entire web — which is why it's a more reliable signal for "internet is actually working."

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.85%. Comparing base (1bc58f6) to head (cb71c7c).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #358   +/-   ##
========================================
  Coverage    73.85%   73.85%           
========================================
  Files            6        6           
  Lines          631      631           
========================================
  Hits           466      466           
  Misses         165      165           

Flag	Coverage Δ
unittests	73.85% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[MateoLostanlen]

Small efficiency comment but ok for me, thanks

[fe51]

Fixed @MateoLostanlen , can you approve and I merge after :) ?

[MateoLostanlen]

hi @fe51 can you fix style first ?

[fe51]

done @MateoLostanlen ! thanks for the catch