Validate host/target fields (hostname or IP; host allows */** wildcards)

Backend (utils/hostname_validate.js, enforced in routes/host.js on create/update):
- host: IPv4 or a wildcard pattern whose labels may be normal, "*" (one
  fragment) or "**" (any depth, incl. a bare "**" catch-all) — matching
  Host.lookUp. Lowered Host.host min length to 1 so "**"/"*" pass the model.
- target (ip): IPv4 or a strict hostname, no wildcards.
- Both reject scheme, "/", ":" and whitespace; 422 with per-field keys.

Frontend (val.js) mirrors the rules: host/target validators + hosts.ejs fields
point at them. Unit tests in test/unit/hostname_validate.test.js.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

nodejs/views/hosts.ejs

@@ -368,7 +368,7 @@
 							Incoming Host Name
 						</label>
 						<div>
-							<input type="text" name="host" class="form-control" placeholder="ex: proxy.cloud-ops.net" validate=":3" >
+							<input type="text" name="host" class="form-control" placeholder="ex: proxy.cloud-ops.net, *.cloud-ops.net, **.cloud-ops.net, or **" validate="host" >
 							<b class="invalid-feedback"></b>
 						</div>
 					</div>
@@ -419,7 +419,7 @@
 						<label for="ip" class="form-label">
 							Target IP or Host Name
 						</label>
-						<input type="text" name="ip" class="form-control" placeholder="ex: 10.10.10.10" validate=":3" />
+						<input type="text" name="ip" class="form-control" placeholder="ex: 10.10.10.10 or app.internal.net" validate="target:3" />
 						<b class="invalid-feedback"></b>
 					</div>