Fix host resolution and concurrent cache updates

README.md

@@ -250,6 +250,8 @@ Resolution order:
 2. **Domain expansion** — if the input contains no dot, each configured domain is appended and tried (`web01` → `web01.example.com`). If no cache hit, NetBox is queried with the expanded name.
 3. **Hyphen folding** (`strip_hyphens: true`) — hyphens are inserted back before looking up in the cache (`fsn1web01` → `fsn1-web01.example.com`). This only works when the host is already cached; run `netssh cache refresh` first.
 
+Domains may be configured with or without a leading dot. If several cached hosts normalize to the same shortcut, the connection is rejected; use the full hostname. Live host lookups check every result page and reject duplicate exact names.
+
 | Input | Config | Resolved as |
 |-------|--------|-------------|
 | `web01` | `domains: [.example.com]` | `web01.example.com` |
@@ -401,6 +403,8 @@ netssh search app-           # prints matching hostnames, one per line
 
 Strategies are tried in the configured order; the first to succeed wins.
 
+Cache refresh uses the same strategies as a direct connection. To allow the primary IP as a fallback, include `primary_ip` in the strategy list. Hosts that cannot be resolved, or have ambiguous names in the refresh results, are removed from the cache and reported as warnings.
+
 | Name | Description |
 |------|-------------|
 | `primary_ip` | Returns the `primary_ip4` (or `primary_ip6`) set in NetBox. No extra API call. |