v1.6.0 — rule validation: user input can no longer break the router

WHAT
- New sanitize_pattern() in the proxy router: single canonicalization point
  for every guard rule. Strips pasted URL noise (https:// scheme, paths,
  query strings, ports), lowercases, and rejects anything unmatchable.
- WildcardRouter::new / update_rules silently drop invalid patterns from
  config.toml instead of carrying broken matchers.
- Dashboard POST /api/rules validates input and shows a red inline error
  (glow-styled) under the form instead of failing silently; success clears it.

WHY
- Users naturally paste full URLs like https://www.sber.ru/ into the rule
  form; slashes and schemes poisoned wildcard matching and broke parsing.
- Config files hand-edited with the same noise are now self-healing.