feat: add network.force_ipv4 config to fix IPv6 timeout issues (#8196)

On servers with broken or unreachable IPv6, Python's socket.getaddrinfo
returns AAAA records first. urllib/httpx/requests all try IPv6 connections
first and hang for the full TCP timeout before falling back to IPv4. This
affects web_extract, web_search, the OpenAI SDK, and all HTTP tools.

Adds network.force_ipv4 config option (default: false) that monkey-patches
socket.getaddrinfo to resolve as AF_INET when the caller didn't specify a
family. Falls back to full resolution if no A record exists, so pure-IPv6
hosts still work.

Applied early at all three entry points (CLI, gateway, cron scheduler)
before any HTTP clients are created.

Reported by user @29n — Chinese Ubuntu server with unreachable IPv6 causing
timeouts on lobste.rs and other IPv6-enabled sites while Google/GitHub
worked fine (IPv4-only resolution).

hermes_cli/main.py

@@ -151,6 +151,18 @@ try:
 except Exception:
     pass  # best-effort — don't crash the CLI if logging setup fails
 
+# Apply IPv4 preference early, before any HTTP clients are created.
+try:
+    from hermes_cli.config import load_config as _load_config_early
+    from hermes_constants import apply_ipv4_preference as _apply_ipv4
+    _early_cfg = _load_config_early()
+    _net = _early_cfg.get("network", {})
+    if isinstance(_net, dict) and _net.get("force_ipv4"):
+        _apply_ipv4(force=True)
+    del _early_cfg, _net
+except Exception:
+    pass  # best-effort — don't crash if config isn't available yet
+
 import logging
 import time as _time
 from datetime import datetime