feat(dashboard): breadcrumbs that follow how you reached a page

Detail pages carry a breadcrumb bar built from a per-tab trail in
sessionStorage: following a link from a page on the trail extends it,
going back to one cuts it there, and opening a page directly shows its
natural parents. The property 3D view's back button goes to the previous
crumb, and the property page renames its crumb once its name loads.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dDashboardServer/static/js/common.js

@@ -353,6 +353,83 @@
 	document.addEventListener('shown.bs.collapse', function (e) { if (e.target.dataset.prefOpen) Prefs.set(e.target.dataset.prefOpen, true); });
 	document.addEventListener('hidden.bs.collapse', function (e) { if (e.target.dataset.prefOpen) Prefs.set(e.target.dataset.prefOpen, false); });
 
+	/**
+	 * Breadcrumbs that follow how you actually got to a page, kept per browser tab (sessionStorage).
+	 * A detail page has <nav data-crumbs data-crumb-label="..."> holding its natural parents as links (what shows when
+	 * the page is opened directly); every other page starts a new trail. Arriving from a page on the trail (by link
+	 * or script, seen through the same-origin referrer) continues it from there; returning to a page on the trail
+	 * (back, a crumb, reload) cuts it back to that page. Crumbs.label(text) renames the current page once its name
+	 * has loaded. A link marked data-crumb-back points at the previous page on the trail.
+	 */
+	window.Crumbs = (function () {
+		var KEY = 'dash.trail', MAX = 7;
+		var here = window.location.pathname + window.location.search;
+		var nav = document.querySelector('[data-crumbs]');
+		function load() {
+			try { var t = JSON.parse(sessionStorage.getItem(KEY) || '[]'); return Array.isArray(t) ? t : []; } catch (e) { return []; }
+		}
+		function save(t) { try { sessionStorage.setItem(KEY, JSON.stringify(t)); } catch (e) { /* storage unavailable */ } }
+		function indexOf(t, href) { for (var i = 0; i < t.length; i++) if (t[i] && t[i].href === href) return i; return -1; }
+		function titleLabel() {
+			var title = document.title.replace(/\s*-\s*DarkflameServer\s*$/, '').trim();
+			return !title || title === 'DarkflameServer' ? 'Home' : title;
+		}
+		var from = '';
+		try {
+			var ref = document.referrer ? new URL(document.referrer) : null;
+			if (ref && ref.origin === window.location.origin) from = ref.pathname + ref.search;
+		} catch (e) {}
+
+		var trail = load(), label = nav ? (nav.dataset.crumbLabel || titleLabel()) : titleLabel();
+		if (!nav) {
+			// Lists and other top-level pages start the trail
+			trail = [{ href: here, label: label }];
+		} else {
+			var at = indexOf(trail, here), came = from && from !== here ? indexOf(trail, from) : -1;
+			if (at >= 0) trail = trail.slice(0, at + 1);
+			else if (came >= 0) trail = trail.slice(0, came + 1).concat([{ href: here, label: label }]);
+			else {
+				// Opened directly or from outside the trail: the page's natural parents
+				trail = Array.prototype.map.call(nav.querySelectorAll('a[href]'), function (a) {
+					return { href: a.getAttribute('href'), label: a.textContent.trim() };
+				}).concat([{ href: here, label: label }]);
+			}
+			if (trail.length > MAX) trail = [trail[0]].concat(trail.slice(trail.length - MAX + 1));
+		}
+		save(trail);
+
+		function render() {
+			if (!nav) return;
+			nav.hidden = trail.length < 2;
+			var ol = document.createElement('ol');
+			ol.className = 'breadcrumb mb-3';
+			trail.forEach(function (c, i) {
+				var li = document.createElement('li');
+				li.className = 'breadcrumb-item' + (i === trail.length - 1 ? ' active' : '');
+				if (i === trail.length - 1) { li.setAttribute('aria-current', 'page'); li.textContent = c.label; }
+				else { var a = document.createElement('a'); a.href = c.href; a.textContent = c.label; li.appendChild(a); }
+				ol.appendChild(li);
+			});
+			nav.replaceChildren(ol);
+			var prev = trail.length > 1 ? trail[trail.length - 2] : null;
+			document.querySelectorAll('a[data-crumb-back]').forEach(function (a) {
+				if (!prev) return;
+				a.href = prev.href;
+				a.textContent = '← ' + prev.label;
+			});
+		}
+		render();
+		return {
+			label: function (text) {
+				if (!nav || !text) return;
+				trail[trail.length - 1].label = String(text);
+				save(trail);
+				render();
+			},
+			previous: function () { return trail.length > 1 ? trail[trail.length - 2] : null; }
+		};
+	})();
+
 	if (window.jQuery && $.fn.dataTable) {
 		// Columns without a custom renderer are inserted as HTML by default; render them as text instead
 		$.extend(true, $.fn.dataTable.defaults, {

dDashboardServer/templates/account-view.jinja2

@@ -3,9 +3,7 @@
 {% block title %}Account #{{ account.id }} - DarkflameServer{% endblock %}
 
 {% block content %}
-{% if can.accounts_view %}
-<a href="/accounts" class="text-decoration-none mb-3 d-inline-block">&larr; Back to Accounts</a>
-{% endif %}
+<nav data-crumbs data-crumb-label="{{ account.name }}" aria-label="Breadcrumb"><ol class="breadcrumb mb-3">{% if can.accounts_view %}<li class="breadcrumb-item"><a href="/accounts">Accounts</a></li>{% endif %}<li class="breadcrumb-item active" aria-current="page">{{ account.name }}</li></ol></nav>
 
 <div class="card mb-4" id="account" data-account-id="{{ account.id }}" data-gm-level="{{ account.gm_level }}" data-email="{{ account.email }}" data-account-name="{{ account.name }}" data-self="{% if is_self %}1{% endif %}" data-can-moderate="{% if manage.moderation %}1{% endif %}">
 	<div class="card-header d-flex justify-content-between align-items-center">

dDashboardServer/templates/bug_report-view.jinja2

@@ -3,7 +3,7 @@
 {% block title %}Bug Report #{{ report.id }} - DarkflameServer{% endblock %}
 
 {% block content %}
-<a href="/bug_reports" class="text-decoration-none mb-3 d-inline-block">&larr; Back to Bug Reports</a>
+<nav data-crumbs data-crumb-label="Bug Report #{{ report.id }}" aria-label="Breadcrumb"><ol class="breadcrumb mb-3"><li class="breadcrumb-item"><a href="/bug_reports">Bug Reports</a></li><li class="breadcrumb-item active" aria-current="page">Bug Report #{{ report.id }}</li></ol></nav>
 
 <div class="card mb-4" id="report" data-report-id="{{ report.id }}">
 	<div class="card-header d-flex justify-content-between align-items-center">

dDashboardServer/templates/character-view.jinja2

@@ -42,11 +42,7 @@
 {% endblock %}
 
 {% block content %}
-{% if can.characters_view %}
-<a href="/characters" class="text-decoration-none mb-3 d-inline-block">&larr; Back to Characters</a>
-{% else %}
-<a href="/" class="text-decoration-none mb-3 d-inline-block">&larr; Back to your characters</a>
-{% endif %}
+<nav data-crumbs data-crumb-label="{{ character.name }}" aria-label="Breadcrumb"><ol class="breadcrumb mb-3">{% if can.characters_view %}<li class="breadcrumb-item"><a href="/characters">Characters</a></li>{% else %}<li class="breadcrumb-item"><a href="/">Your characters</a></li>{% endif %}<li class="breadcrumb-item active" aria-current="page">{{ character.name }}</li></ol></nav>
 
 <div class="row g-4">
 	<div class="col-lg-4">

dDashboardServer/templates/play_key-view.jinja2

@@ -3,7 +3,7 @@
 {% block title %}Play Key #{{ key.id }} - DarkflameServer{% endblock %}
 
 {% block content %}
-<a href="/play_keys" class="text-decoration-none mb-3 d-inline-block">&larr; Back to Play Keys</a>
+<nav data-crumbs data-crumb-label="Play Key #{{ key.id }}" aria-label="Breadcrumb"><ol class="breadcrumb mb-3"><li class="breadcrumb-item"><a href="/play_keys">Play Keys</a></li><li class="breadcrumb-item active" aria-current="page">Play Key #{{ key.id }}</li></ol></nav>
 
 <div class="row g-4">
 	<div class="col-lg-5">

dDashboardServer/templates/property-3d.jinja2

@@ -23,9 +23,10 @@
 
 {% block content %}
 {# Also the showcase's read-only view of approved public properties (Showcase.cpp passes showcase) #}
+{% if not exists("showcase") %}<nav data-crumbs data-crumb-label="3D view" aria-label="Breadcrumb"><ol class="breadcrumb mb-2">{% if can.properties_view %}<li class="breadcrumb-item"><a href="/properties">Properties</a></li>{% endif %}<li class="breadcrumb-item"><a href="/properties/{{ property_id }}">Property {{ property_id }}</a></li><li class="breadcrumb-item active" aria-current="page">3D view</li></ol></nav>{% endif %}
 <div id="property" data-property-id="{{ property_id }}" data-behavior-rules="{{ behavior_rules }}" data-showcase="{% if exists("showcase") %}1{% endif %}">
 	<div class="d-flex flex-wrap align-items-center gap-2 mb-2">
-		{% if exists("showcase") %}<a href="/showcase" class="btn btn-sm btn-outline-secondary">&larr; Showcase</a>{% else %}<a href="/properties/{{ property_id }}" class="btn btn-sm btn-outline-secondary">&larr; Property</a>{% endif %}
+		{% if exists("showcase") %}<a href="/showcase" class="btn btn-sm btn-outline-secondary">&larr; Showcase</a>{% else %}<a href="/properties/{{ property_id }}" class="btn btn-sm btn-outline-secondary" data-crumb-back>&larr; Property</a>{% endif %}
 		<div class="me-auto">
 			<h5 class="mb-0 d-inline" id="propName">Loading&hellip;</h5>
 			<span class="small text-body-secondary ms-2" id="propMeta"></span>

dDashboardServer/templates/property-view.jinja2

@@ -3,9 +3,7 @@
 {% block title %}Property - DarkflameServer{% endblock %}
 
 {% block content %}
-{% if can.properties_view %}
-<a href="/properties" class="text-decoration-none mb-3 d-inline-block">&larr; Back to Properties</a>
-{% endif %}
+<nav data-crumbs data-crumb-label="Property {{ property_id }}" aria-label="Breadcrumb"><ol class="breadcrumb mb-3">{% if can.properties_view %}<li class="breadcrumb-item"><a href="/properties">Properties</a></li>{% endif %}<li class="breadcrumb-item active" aria-current="page">Property {{ property_id }}</li></ol></nav>
 
 <div id="property" data-property-id="{{ property_id }}">
 	<div class="card mb-4">
@@ -189,6 +187,7 @@ function load() {
 		if (p.success === false) { setText('propName', p.error); return; }
 		loaded = p;
 		setText('propName', p.name || 'Unnamed property');
+		Crumbs.label(p.name || 'Unnamed property');
 		// This property's own events and statistics (each property is its own instance of the zone, told apart by the clone)
 		const economy = document.getElementById('propEconomy');
 		if (economy && p.clone_id) {