Add header help icon and in-app docs search

- A ? icon in the top-right header deep-links to the doc most relevant to
  the current page (client-side path mapping, same pattern already used
  for top-nav active-link highlighting -- no server-side "current section"
  local exists to key off of instead). Falls back to the docs index.
- GET /docs/search does a plain line-substring search over the existing
  allowlisted doc set. No new dependency, stays usable with no internet
  access.

Bumps to v1.1.10.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KDEx8ghuZR61pqPXc6da9C

nodejs/views/top.ejs

@@ -62,6 +62,9 @@
 					</li>
 				</ul>
 				<div class="form-inline mt-2 mt-md-0">
+					<a id="cl-help" class="nav-link text-light me-3" href="/docs" title="Help">
+						<i class="fa-solid fa-circle-question"></i>
+					</a>
 					<a id="cl-username" class="navbar-text text-light me-3" href="/profile" style="display: none;">
 						<i class="fa-solid fa-user me-1"></i><span id="cl-username-text"></span>
 					</a>
@@ -102,6 +105,21 @@
 				sessionStorage.setItem('update-banner-dismissed', '1');
 			}
 
+			// Deep-link the header help icon to whichever doc is most relevant to
+			// the current page. No server-side "current section" local exists
+			// (every res.render() call shares one values object, see
+			// routes/render.js), so this follows the same client-side
+			// path-matching convention already used for the top-nav active-link
+			// highlighting just below. Unmapped pages fall back to the docs
+			// index (already /docs, the anchor's default).
+			var HELP_DOCS_BY_PATH = {
+				'/hosts': 'installation',
+				'/dns': 'installation',
+				'/users': 'architecture',
+				'/permissions': 'architecture',
+				'/groups': 'architecture',
+			};
+
 			$(document).ready(function(){
 
 				// Set the correct link to active in the top nav bar
@@ -113,6 +131,9 @@
 					}
 				})
 
+				let helpSlug = HELP_DOCS_BY_PATH[window.location.pathname.toLocaleLowerCase()];
+				if(helpSlug) $('#cl-help').attr('href', '/docs/' + helpSlug);
+
 				// Set the correct login/logout button, and reveal admin-only nav
 				// items for global admins.
 				app.auth.isLoggedIn(function(error, data){