diff --git a/.badges/e2e-tests.json b/.badges/e2e-tests.json
index 31f5ca4e..742c162b 100644
--- a/.badges/e2e-tests.json
+++ b/.badges/e2e-tests.json
@@ -1 +1 @@
-{"schemaVersion":1,"label":"e2e tests","message":"768 passed","color":"brightgreen"}
+{"schemaVersion":1,"label":"e2e tests","message":"769 passed","color":"brightgreen"}
diff --git a/.badges/frontend-coverage.json b/.badges/frontend-coverage.json
index f2f425ed..8a281f7b 100644
--- a/.badges/frontend-coverage.json
+++ b/.badges/frontend-coverage.json
@@ -1 +1 @@
-{"schemaVersion":1,"label":"frontend coverage","message":"36.25%","color":"red"}
+{"schemaVersion":1,"label":"frontend coverage","message":"35.66%","color":"red"}
diff --git a/.eslintrc.json b/.eslintrc.json
index 80f397a9..d178d5df 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -52,6 +52,7 @@
     "ROLE_STYLE": "readonly",
     "ROUTE_TYPES": "readonly",
     "RegionFilter": "readonly",
+    "RegionShowAll": "readonly",
     "SITE_CONFIG": "readonly",
     "SKEW_SEVERITY_COLORS": "readonly",
     "SKEW_SEVERITY_LABELS": "readonly",
diff --git a/cmd/server/config.go b/cmd/server/config.go
index 661ca4bc..2c594c5f 100644
--- a/cmd/server/config.go
+++ b/cmd/server/config.go
@@ -359,9 +359,11 @@ func LoadConfig(baseDirs ...string) (*Config, error) {
 			continue
 		}
 		cfg.NormalizeTimestampConfig()
+		applyCORSEnv(cfg)
 		return cfg, nil
 	}
 	cfg.NormalizeTimestampConfig()
+	applyCORSEnv(cfg)
 	return cfg, nil // defaults
 }
 
diff --git a/cmd/server/cors.go b/cmd/server/cors.go
index 9edc1ed6..9ed42b9b 100644
--- a/cmd/server/cors.go
+++ b/cmd/server/cors.go
@@ -1,10 +1,47 @@
 package main
 
-import "net/http"
+import (
+	"net/http"
+	"os"
+	"strings"
+)
+
+// applyCORSEnv overlays cfg.CORSAllowedOrigins from the CORS_ALLOWED_ORIGINS
+// env var when it is set and non-empty. Tokens are comma-separated, trimmed,
+// and empties dropped. The env var is the ops-friendly override; it lets
+// operators add cross-domain embed origins without editing config.json
+// (issue #1369). An unset or empty env var leaves cfg untouched, so
+// per-deployment config.json values still apply.
+func applyCORSEnv(cfg *Config) {
+	raw, ok := os.LookupEnv("CORS_ALLOWED_ORIGINS")
+	if !ok {
+		return
+	}
+	parts := strings.Split(raw, ",")
+	out := make([]string, 0, len(parts))
+	for _, p := range parts {
+		s := strings.TrimSpace(p)
+		if s != "" {
+			out = append(out, s)
+		}
+	}
+	if len(out) == 0 {
+		// Env var present but only whitespace — treat as unset, do not clobber.
+		return
+	}
+	cfg.CORSAllowedOrigins = out
+}
 
 // corsMiddleware returns a middleware that sets CORS headers based on the
 // configured allowed origins. When CORSAllowedOrigins is empty (default),
 // no Access-Control-* headers are added, preserving browser same-origin policy.
+//
+// Embed contract (issue #1369): the cross-domain surface is read-only. The
+// middleware advertises only GET, HEAD, and OPTIONS in Access-Control-Allow-
+// Methods so iframes / server-side fetchers cannot opt into POST/PUT/DELETE
+// via CORS. Same-origin writes (admin UI, API-key holders on the canonical
+// origin) are unaffected — they never go through the preflight path.
+// Credentialed CORS is intentionally NOT enabled.
 func (s *Server) corsMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		origins := s.cfg.CORSAllowedOrigins
@@ -52,7 +89,8 @@ func (s *Server) corsMiddleware(next http.Handler) http.Handler {
 			w.Header().Set("Access-Control-Allow-Origin", reqOrigin)
 			w.Header().Set("Vary", "Origin")
 		}
-		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
+		// Read-only embed contract — see comment above.
+		w.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, OPTIONS")
 		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, X-API-Key")
 
 		// Handle preflight
diff --git a/cmd/server/cors_embed_1369_test.go b/cmd/server/cors_embed_1369_test.go
new file mode 100644
index 00000000..d57b82fe
--- /dev/null
+++ b/cmd/server/cors_embed_1369_test.go
@@ -0,0 +1,93 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+)
+
+// Issue #1369: CORS_ALLOWED_ORIGINS env override + embed support.
+//
+// Red commit: these tests fail until LoadConfig honors the env var and the
+// CORS middleware advertises GET/HEAD/OPTIONS (the embed contract is
+// read-only cross-origin access).
+
+// TestCORS_EnvOverridesConfig — env var CORS_ALLOWED_ORIGINS replaces config.
+func TestCORS_EnvOverridesConfig_1369(t *testing.T) {
+	t.Setenv("CORS_ALLOWED_ORIGINS", "https://blog.example.com,https://embed.example.com")
+	cfg, err := LoadConfig("/nonexistent")
+	if err != nil {
+		t.Fatalf("LoadConfig: %v", err)
+	}
+	if len(cfg.CORSAllowedOrigins) != 2 {
+		t.Fatalf("expected 2 origins from env, got %v", cfg.CORSAllowedOrigins)
+	}
+	if cfg.CORSAllowedOrigins[0] != "https://blog.example.com" ||
+		cfg.CORSAllowedOrigins[1] != "https://embed.example.com" {
+		t.Fatalf("env parse wrong: %v", cfg.CORSAllowedOrigins)
+	}
+}
+
+// TestCORS_EnvEmptyKeepsConfig — empty env var does not clobber file config.
+func TestCORS_EnvEmptyKeepsConfig_1369(t *testing.T) {
+	os.Unsetenv("CORS_ALLOWED_ORIGINS")
+	cfg := &Config{CORSAllowedOrigins: []string{"https://example.com"}}
+	applyCORSEnv(cfg)
+	if len(cfg.CORSAllowedOrigins) != 1 || cfg.CORSAllowedOrigins[0] != "https://example.com" {
+		t.Fatalf("unset env should not clobber config; got %v", cfg.CORSAllowedOrigins)
+	}
+}
+
+// TestCORS_EnvTrimsWhitespace — comma-separated env tokens are trimmed.
+func TestCORS_EnvTrimsWhitespace_1369(t *testing.T) {
+	t.Setenv("CORS_ALLOWED_ORIGINS", "  https://a.example  , https://b.example ")
+	cfg := &Config{}
+	applyCORSEnv(cfg)
+	if len(cfg.CORSAllowedOrigins) != 2 {
+		t.Fatalf("expected 2, got %v", cfg.CORSAllowedOrigins)
+	}
+	if cfg.CORSAllowedOrigins[0] != "https://a.example" || cfg.CORSAllowedOrigins[1] != "https://b.example" {
+		t.Fatalf("not trimmed: %v", cfg.CORSAllowedOrigins)
+	}
+}
+
+// TestCORS_EmbedContractGETHEAD — embed contract is read-only; the
+// Access-Control-Allow-Methods header must advertise GET, HEAD, OPTIONS only
+// (no POST/PUT/DELETE) so iframes/server-side fetchers know writes are not
+// CORS-permitted. DJB hardening: minimum surface.
+func TestCORS_EmbedContractGETHEAD_1369(t *testing.T) {
+	srv := newTestServerWithCORS([]string{"https://embed.example.com"})
+	handler := srv.corsMiddleware(dummyHandler)
+
+	req := httptest.NewRequest("GET", "/api/health", nil)
+	req.Header.Set("Origin", "https://embed.example.com")
+	rr := httptest.NewRecorder()
+	handler.ServeHTTP(rr, req)
+
+	methods := rr.Header().Get("Access-Control-Allow-Methods")
+	if methods != "GET, HEAD, OPTIONS" {
+		t.Fatalf("expected read-only methods 'GET, HEAD, OPTIONS', got %q", methods)
+	}
+}
+
+// TestCORS_PreflightPOSTRejected — preflight asking for POST from an allowed
+// origin must NOT echo POST in Allow-Methods. The middleware advertises only
+// the read-only set; preflight succeeds (browser then blocks the POST).
+func TestCORS_PreflightPOSTRejected_1369(t *testing.T) {
+	srv := newTestServerWithCORS([]string{"https://embed.example.com"})
+	handler := srv.corsMiddleware(dummyHandler)
+
+	req := httptest.NewRequest("OPTIONS", "/api/anything", nil)
+	req.Header.Set("Origin", "https://embed.example.com")
+	req.Header.Set("Access-Control-Request-Method", "POST")
+	rr := httptest.NewRecorder()
+	handler.ServeHTTP(rr, req)
+
+	if rr.Code != http.StatusNoContent {
+		t.Fatalf("preflight expected 204, got %d", rr.Code)
+	}
+	if got := rr.Header().Get("Access-Control-Allow-Methods"); got != "GET, HEAD, OPTIONS" {
+		t.Fatalf("preflight must advertise read-only methods only, got %q", got)
+	}
+}
diff --git a/cmd/server/cors_test.go b/cmd/server/cors_test.go
index acafaaee..676016a0 100644
--- a/cmd/server/cors_test.go
+++ b/cmd/server/cors_test.go
@@ -51,7 +51,7 @@ func TestCORS_AllowlistMatch(t *testing.T) {
 	if v := rr.Header().Get("Access-Control-Allow-Origin"); v != "https://good.example" {
 		t.Fatalf("expected origin echo, got %q", v)
 	}
-	if v := rr.Header().Get("Access-Control-Allow-Methods"); v != "GET, POST, OPTIONS" {
+	if v := rr.Header().Get("Access-Control-Allow-Methods"); v != "GET, HEAD, OPTIONS" {
 		t.Fatalf("expected methods header, got %q", v)
 	}
 	if v := rr.Header().Get("Access-Control-Allow-Headers"); v != "Content-Type, X-API-Key" {
diff --git a/config.example.json b/config.example.json
index beccc1d4..dc7aa684 100644
--- a/config.example.json
+++ b/config.example.json
@@ -17,6 +17,8 @@
     "_comment": "vacuumOnStartup: run one-time full VACUUM to enable incremental auto-vacuum on existing DBs. Executed by the INGESTOR at startup, BEFORE the MQTT subscriber starts (#1283), so there is no contention with concurrent writes. Blocks ingestor startup for minutes on large DBs; requires 2x DB file size in free disk space. incrementalVacuumPages: free pages returned to OS after each retention reaper cycle (default 1024). See #919."
   },
   "_comment_ingestorStats": "Ingestor publishes a 1-Hz stats snapshot consumed by the server's /api/perf/io and /api/perf/write-sources endpoints (#1120). Path is configured via the CORESCOPE_INGESTOR_STATS environment variable on the INGESTOR process. Default: /tmp/corescope-ingestor-stats.json. The writer uses O_NOFOLLOW + 0o600, so a pre-planted symlink in /tmp cannot be used to clobber an arbitrary file. SECURITY: in shared-tmp environments (multi-tenant hosts), point CORESCOPE_INGESTOR_STATS at a private directory like /var/lib/corescope/ingestor-stats.json that only the corescope user can write to.",
+  "corsAllowedOrigins": [],
+  "_comment_corsAllowedOrigins": "Cross-origin allowlist for embed scenarios (#1369). Exact-match origins, e.g. [\"https://blog.example.com\", \"https://embed.example.com\"]. When empty (default), no Access-Control-* headers are sent and browsers enforce same-origin. When non-empty, only the listed origins receive CORS headers, and Access-Control-Allow-Methods is limited to GET, HEAD, OPTIONS (the cross-domain surface is read-only — same-origin admin writes are unaffected). Use [\"*\"] to allow any origin (NOT recommended for write-capable deployments). Operators can override per-deployment with the CORS_ALLOWED_ORIGINS environment variable (comma-separated). No credentialed CORS is enabled. To embed the map or channels pages cross-domain, add the embedding origin here and use the URL pattern '/#/map?embed=1' or '/#/channels?embed=1' — embed mode hides the top-nav, bottom-nav, and side drawer for full-bleed iframe rendering.",
   "https": {
     "cert": "/path/to/cert.pem",
     "key": "/path/to/key.pem",
diff --git a/public/app.js b/public/app.js
index f31d39b4..fb35c0e0 100644
--- a/public/app.js
+++ b/public/app.js
@@ -175,6 +175,21 @@ function getHashParams() {
   return new URLSearchParams(location.hash.split('?')[1] || '');
 }
 
+// shouldEmbedRoute — issue #1369. Returns true when the SPA should render in
+// "embed" mode (chrome suppressed: no top-nav, no bottom-nav, no side drawer,
+// content full-bleed). Triggered by ?embed=1 in the hash query string.
+//
+// Allowlisted to /#/map and /#/channels — the two surfaces operators asked
+// for in the cross-domain embed scenario. Other pages have chrome assumptions
+// we are not committing to in embed mode (Tufte: ship narrow, expand later
+// only when there is a real ask).
+function shouldEmbedRoute(basePage, hashSearch) {
+  if (basePage !== 'map' && basePage !== 'channels') return false;
+  if (!hashSearch) return false;
+  var params = new URLSearchParams(hashSearch);
+  return params.get('embed') === '1';
+}
+
 function getDistanceUnit() {
   var stored = localStorage.getItem('meshcore-distance-unit');
   if (stored === 'km') return 'km';
@@ -928,6 +943,14 @@ function navigate() {
   // Pages with fixed-height containers (maps, virtual-scroll, split-panels)
   const fixedPages = { packets: 1, nodes: 1, map: 1, live: 1, channels: 1, 'audio-lab': 1 };
   app.classList.toggle('app-fixed', basePage in fixedPages);
+
+  // Issue #1369: ?embed=1 chrome suppression for cross-domain iframe embeds.
+  // Toggles body.embed; CSS in style.css hides top-nav / bottom-nav / nav-drawer
+  // and zeroes body padding so /#/map and /#/channels render full-bleed.
+  try {
+    var hashSearch = (location.hash.split('?')[1] || '');
+    document.body.classList.toggle('embed', shouldEmbedRoute(basePage, hashSearch));
+  } catch (_) { /* DOM may be missing in some test contexts */ }
   if (pages[basePage]?.init) {
     const t0 = performance.now();
     pages[basePage].init(app, routeParam);
diff --git a/public/live.css b/public/live.css
index 6789b207..fe64c6ca 100644
--- a/public/live.css
+++ b/public/live.css
@@ -449,6 +449,16 @@
 .live-toggles .live-region-filter-container { display: inline-flex; align-items: center; }
 .live-toggles .live-region-filter-container .region-dropdown-trigger { font-size: inherit; padding: 2px 6px; }
 
+/* #1108 — "Show all nodes" sibling of the region dropdown. Reuses the
+   .live-toggles label rhythm so it lines up with the other inline toggles. */
+.live-toggles .live-show-all-region-nodes {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: inherit;
+  white-space: nowrap;
+}
+
 /* ---- Leaflet overrides for dark theme ---- */
 .live-page .leaflet-control-zoom a {
   background: color-mix(in srgb, var(--surface-1) 92%, transparent) !important;
diff --git a/public/live.js b/public/live.js
index 893db5e3..fb39623a 100644
--- a/public/live.js
+++ b/public/live.js
@@ -1424,7 +1424,32 @@
         setObserverIataMap(buildObserverIataMap(data));
       }).catch(function () { /* leave map empty; filter will hide all when active */ });
       RegionFilter.init(rfEl, { dropdown: true });
-      regionFilterChangeHandler = RegionFilter.onChange(function () { /* selection persisted by RegionFilter; future packets reflect it */ });
+      regionFilterChangeHandler = RegionFilter.onChange(function() {
+        // #1108 — when the region selection changes, reload visible map
+        // nodes so non-region nodes disappear (or reappear) immediately.
+        // The packet feed already filters live via packetMatchesRegion.
+        try { loadNodes(); } catch (e) { /* loadNodes not yet defined during init order edge cases */ }
+      });
+      // #1108 — "Show all nodes (faded)" sub-toggle, sibling to the region
+      // dropdown. Off by default = hide non-region nodes; on = legacy
+      // show-everything behavior.
+      (function initShowAllNodesToggle() {
+        if (!window.RegionShowAll) return;
+        var wrap = document.createElement('label');
+        wrap.className = 'live-show-all-region-nodes';
+        wrap.title = 'When a region is selected, show every node on the map (legacy behavior). Off = hide non-region nodes.';
+        var cb = document.createElement('input');
+        cb.type = 'checkbox';
+        cb.id = 'liveShowAllRegionNodes';
+        cb.checked = RegionShowAll.get();
+        wrap.appendChild(cb);
+        wrap.appendChild(document.createTextNode(' Show all nodes'));
+        rfEl.parentNode.insertBefore(wrap, rfEl.nextSibling);
+        cb.addEventListener('change', function() {
+          RegionShowAll.set(cb.checked);
+          try { loadNodes(); } catch (e) {}
+        });
+      })();
     })();
 
     // Node filter input — autocomplete-as-you-type (#1110)
@@ -2286,9 +2311,13 @@
   async function loadNodes(beforeTs) {
     try {
       const aqs = AreaFilter.areaQueryString();
+      // #1108 — honor region selector for visible map nodes unless
+      // "Show all nodes" is enabled. Empty string when no region set.
+      const rqs = (window.RegionFilter && typeof RegionFilter.nodesRegionQueryString === 'function')
+        ? RegionFilter.nodesRegionQueryString() : '';
       const url = beforeTs
-        ? `/api/nodes?limit=2000&before=${encodeURIComponent(new Date(beforeTs).toISOString())}${aqs}`
-        : `/api/nodes?limit=2000${aqs}`;
+        ? `/api/nodes?limit=2000&before=${encodeURIComponent(new Date(beforeTs).toISOString())}${aqs}${rqs}`
+        : `/api/nodes?limit=2000${aqs}${rqs}`;
       // Full reload (no beforeTs): clear existing markers so switching areas
       // removes nodes that no longer belong to the selected area.
       if (!beforeTs) {
diff --git a/public/region-filter.js b/public/region-filter.js
index 31dfbabe..69f88fc7 100644
--- a/public/region-filter.js
+++ b/public/region-filter.js
@@ -213,6 +213,49 @@
     if (_container) render(_container);
   }
 
+  /**
+   * #1108 — "Show all nodes (faded)" toggle.
+   *
+   * When a region is selected, the default behavior (showAll = false) is to
+   * HIDE non-region nodes on the map: the operator is looking at a region for
+   * a reason, and far-away nodes are visual noise. When the toggle is ON
+   * (showAll = true), legacy behavior is restored — all nodes load, region
+   * scoping only applies to packet feeds / metrics.
+   *
+   * State persists across reloads in localStorage. Default: false (hide).
+   */
+  var SHOW_ALL_KEY = 'mc-region-show-all-nodes';
+  var _showAllListeners = [];
+  function showAllGet() {
+    try { return localStorage.getItem(SHOW_ALL_KEY) === 'true'; }
+    catch (e) { return false; }
+  }
+  function showAllSet(v) {
+    var bool = !!v;
+    try {
+      if (bool) localStorage.setItem(SHOW_ALL_KEY, 'true');
+      else localStorage.removeItem(SHOW_ALL_KEY);
+    } catch (e) { /* ignore */ }
+    _showAllListeners.forEach(function (fn) { fn(bool); });
+  }
+  function showAllOnChange(fn) { _showAllListeners.push(fn); return fn; }
+  function showAllOffChange(fn) {
+    _showAllListeners = _showAllListeners.filter(function (f) { return f !== fn; });
+  }
+
+  /**
+   * Build a node-list query fragment that respects the "show all nodes" toggle.
+   * Returns "&region=SJC,SFO" only when a region is selected AND showAll is
+   * OFF; otherwise empty string. Use this for /api/nodes? requests on map
+   * surfaces where the operator expects the visible markers to follow the
+   * region selector. Other surfaces (packets, metrics) should keep using
+   * regionQueryString() which is unconditional.
+   */
+  function nodesRegionQueryString() {
+    if (showAllGet()) return '';
+    return regionQueryString();
+  }
+
   // Expose globally
   window.RegionFilter = {
     init: initFilter,
@@ -220,9 +263,17 @@
     getSelected: getSelected,
     getRegionParam: getRegionParam,
     regionQueryString: regionQueryString,
+    nodesRegionQueryString: nodesRegionQueryString,
     onChange: onChange,
     offChange: offChange,
     fetchRegions: fetchRegions,
     setSelected: setSelected
   };
+  window.RegionShowAll = {
+    get: showAllGet,
+    set: showAllSet,
+    onChange: showAllOnChange,
+    offChange: showAllOffChange,
+    STORAGE_KEY: SHOW_ALL_KEY
+  };
 })();
diff --git a/public/style.css b/public/style.css
index 34d67493..aaf9f8ff 100644
--- a/public/style.css
+++ b/public/style.css
@@ -4659,3 +4659,20 @@ body { touch-action: pan-y; }
   }
   .mc-route-edge { stroke: CanvasText !important; }
 }
+
+/* ===========================================================================
+   Issue #1369 — embed mode (?embed=1 on /#/map and /#/channels)
+   Hide all chrome for full-bleed cross-domain iframe embeds. body.embed is
+   toggled in app.js navigate() based on shouldEmbedRoute().
+   =========================================================================== */
+body.embed .top-nav,
+body.embed [data-bottom-nav],
+body.embed .nav-drawer,
+body.embed .nav-drawer-backdrop { display: none !important; }
+body.embed { padding: 0 !important; margin: 0 !important; }
+/* App container occupies full viewport in embed mode — top-nav (52px) and
+   bottom-nav reserve are gone, so reclaim the full dvh. */
+body.embed #app.app-fixed {
+  height: 100vh !important;
+  height: 100dvh !important;
+}
diff --git a/test-1108-region-hide-nodes.js b/test-1108-region-hide-nodes.js
new file mode 100644
index 00000000..c693bfee
--- /dev/null
+++ b/test-1108-region-hide-nodes.js
@@ -0,0 +1,93 @@
+/**
+ * Issue #1108 — Hide non-region nodes when a region is selected on Live map.
+ *
+ * Unit tests for the public helpers added to region-filter.js:
+ *   - RegionShowAll.get() / set() with localStorage persistence
+ *   - RegionFilter.nodesRegionQueryString() — returns &region= when filter
+ *     active AND showAll is OFF; empty string otherwise.
+ *
+ * These tests load the module via vm sandbox with mocked globals
+ * (no DOM, no fetch). Mirrors the pattern from test-area-filter.js.
+ */
+'use strict';
+const vm = require('vm');
+const fs = require('fs');
+const assert = require('assert');
+
+let passed = 0, failed = 0;
+function test(name, fn) {
+  try { fn(); passed++; console.log(`  \u2713 ${name}`); }
+  catch (e) { failed++; console.error(`  \u2717 ${name}: ${e.message}`); }
+}
+
+function buildCtx(initialStorage) {
+  const storage = Object.assign(Object.create(null), initialStorage || {});
+  const localStorage = {
+    getItem: (k) => (k in storage ? storage[k] : null),
+    setItem: (k, v) => { storage[k] = String(v); },
+    removeItem: (k) => { delete storage[k]; },
+  };
+  const ctx = {
+    window: {},
+    document: { addEventListener() {} },
+    localStorage,
+    fetch: async () => ({ json: async () => ({}) }),
+    console,
+    setTimeout, clearTimeout,
+  };
+  ctx.window = ctx;
+  vm.createContext(ctx);
+  const src = fs.readFileSync(__dirname + '/public/region-filter.js', 'utf8');
+  vm.runInContext(src, ctx);
+  return ctx;
+}
+
+console.log('#1108 RegionShowAll + nodesRegionQueryString unit tests');
+
+test('RegionShowAll exposed on window', () => {
+  const ctx = buildCtx();
+  assert.ok(ctx.window.RegionShowAll, 'expected window.RegionShowAll');
+  assert.strictEqual(typeof ctx.window.RegionShowAll.get, 'function');
+  assert.strictEqual(typeof ctx.window.RegionShowAll.set, 'function');
+});
+
+test('RegionShowAll.get() defaults to false', () => {
+  const ctx = buildCtx();
+  assert.strictEqual(ctx.window.RegionShowAll.get(), false);
+});
+
+test('RegionShowAll.set(true) persists; rebuild loads it back', () => {
+  const ctx = buildCtx();
+  ctx.window.RegionShowAll.set(true);
+  assert.strictEqual(ctx.window.RegionShowAll.get(), true);
+  const ctx2 = buildCtx({ 'mc-region-show-all-nodes': 'true' });
+  assert.strictEqual(ctx2.window.RegionShowAll.get(), true);
+});
+
+test('RegionShowAll.set(false) clears persisted value', () => {
+  const ctx = buildCtx({ 'mc-region-show-all-nodes': 'true' });
+  assert.strictEqual(ctx.window.RegionShowAll.get(), true);
+  ctx.window.RegionShowAll.set(false);
+  assert.strictEqual(ctx.window.RegionShowAll.get(), false);
+});
+
+test('nodesRegionQueryString returns &region= when filter set + showAll off', () => {
+  const ctx = buildCtx({ 'meshcore-region-filter': '["SJC"]' });
+  ctx.window.RegionShowAll.set(false);
+  assert.strictEqual(ctx.window.RegionFilter.nodesRegionQueryString(), '&region=SJC');
+});
+
+test('nodesRegionQueryString empty when showAll on (legacy show-everything behavior)', () => {
+  const ctx = buildCtx({ 'meshcore-region-filter': '["SJC"]' });
+  ctx.window.RegionShowAll.set(true);
+  assert.strictEqual(ctx.window.RegionFilter.nodesRegionQueryString(), '');
+});
+
+test('nodesRegionQueryString empty when no region selected', () => {
+  const ctx = buildCtx();
+  ctx.window.RegionShowAll.set(false);
+  assert.strictEqual(ctx.window.RegionFilter.nodesRegionQueryString(), '');
+});
+
+console.log(`\nResults: ${passed} passed, ${failed} failed`);
+process.exit(failed > 0 ? 1 : 0);
diff --git a/test-embed-mode-1369.js b/test-embed-mode-1369.js
new file mode 100644
index 00000000..480d5f13
--- /dev/null
+++ b/test-embed-mode-1369.js
@@ -0,0 +1,98 @@
+/* Unit tests for issue #1369 embed-mode helper.
+ *
+ * Red commit: shouldEmbedRoute() does not exist yet; this test fails on import.
+ * Green commit: define shouldEmbedRoute(basePage, hashSearch) in public/app.js
+ * and expose for tests.
+ *
+ * The contract:
+ *   - returns true ONLY when basePage is 'map' or 'channels' AND the hash
+ *     query string contains embed=1 (e.g. '#/map?embed=1' → search='embed=1').
+ *   - false for any other route, false when embed param is missing or != '1'.
+ *   - the route-allowlist is deliberate: other pages have chrome assumptions
+ *     that we are not committing to support in embed mode (Tufte: scope tight,
+ *     ship the two surfaces operators asked for, no more).
+ */
+'use strict';
+const vm = require('vm');
+const fs = require('fs');
+const path = require('path');
+const assert = require('assert');
+
+let passed = 0, failed = 0;
+function test(name, fn) {
+  try { fn(); passed++; console.log('  ✅ ' + name); }
+  catch (e) { failed++; console.log('  ❌ ' + name + ': ' + e.message); }
+}
+
+// Load app.js into a sandbox. We only need the helper, so we wrap with a
+// minimal browser shim that no-ops everything app.js touches at import time.
+const appSrc = fs.readFileSync(path.join(__dirname, 'public', 'app.js'), 'utf8');
+const ctx = {
+  window: { addEventListener: () => {}, dispatchEvent: () => {}, matchMedia: () => ({ matches: false }) },
+  document: {
+    readyState: 'complete',
+    documentElement: { setAttribute: () => {}, getAttribute: () => null, classList: { add: () => {}, remove: () => {}, toggle: () => {} } },
+    body: { classList: { add: () => {}, remove: () => {}, toggle: () => {} } },
+    createElement: () => ({ id: '', textContent: '', innerHTML: '', classList: { add: () => {}, remove: () => {} }, setAttribute: () => {}, appendChild: () => {} }),
+    head: { appendChild: () => {} },
+    getElementById: () => null,
+    addEventListener: () => {},
+    querySelectorAll: () => [],
+    querySelector: () => null,
+  },
+  console, Date, Math, JSON, RegExp, Error, TypeError, Map, Set,
+  Array, Object, String, Number, Boolean, parseInt, parseFloat, isNaN, isFinite,
+  encodeURIComponent, decodeURIComponent, URLSearchParams,
+  setTimeout: () => 0, clearTimeout: () => {}, setInterval: () => 0, clearInterval: () => {},
+  fetch: () => Promise.resolve({ json: () => Promise.resolve({}) }),
+  performance: { now: () => Date.now() },
+  localStorage: { getItem: () => null, setItem: () => {}, removeItem: () => {} },
+  location: { hash: '', search: '' },
+  CustomEvent: class {},
+  navigator: { language: 'en-US' },
+  requestAnimationFrame: () => 0,
+};
+ctx.globalThis = ctx;
+ctx.self = ctx;
+try {
+  vm.createContext(ctx);
+  vm.runInContext(appSrc, ctx, { filename: 'app.js' });
+} catch (e) {
+  // app.js does a lot at import; if any helper init blows up, it's fine as
+  // long as shouldEmbedRoute is bound by the time we test it.
+  console.log('  (app.js init threw: ' + e.message + ' — proceeding)');
+}
+
+console.log('issue #1369 — shouldEmbedRoute');
+test('exists', () => {
+  assert.strictEqual(typeof ctx.shouldEmbedRoute, 'function', 'shouldEmbedRoute must be defined on window/global');
+});
+test('map + embed=1 → true', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('map', 'embed=1'), true);
+});
+test('channels + embed=1 → true', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('channels', 'embed=1'), true);
+});
+test('map + embed=1 mixed with other params → true', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('map', 'region=SFO&embed=1&zoom=8'), true);
+});
+test('packets + embed=1 → false (route not in allowlist)', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('packets', 'embed=1'), false);
+});
+test('nodes + embed=1 → false', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('nodes', 'embed=1'), false);
+});
+test('map + no embed param → false', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('map', 'region=SFO'), false);
+});
+test('map + embed=0 → false', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('map', 'embed=0'), false);
+});
+test('map + empty search → false', () => {
+  assert.strictEqual(ctx.shouldEmbedRoute('map', ''), false);
+});
+
+console.log('\n' + '═'.repeat(40));
+console.log('  embed-mode helper: ' + passed + ' passed, ' + failed + ' failed');
+console.log('═'.repeat(40) + '\n');
+if (failed > 0) process.exit(1);