Merge branch 'dev'

- Deduplicate cursor rendering using #uniquePeers() (was showing
  multiple cursors per user from different tabs/sessions)
- Strict same-page filtering: cursors only visible when peers share
  the same effectiveViewId (viewId ?? moduleId)
- Users on different rApps no longer see each other's cursors
- Applied same fixes to focus rings and panel "different view" badge

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/components/rstack-collab-overlay.ts

@@ -400,6 +400,11 @@ export class RStackCollabOverlay extends HTMLElement {
 
 	// ── Local broadcasting ──
 
+	/** Effective view identifier — viewId if set, else moduleId. Used to scope cursor visibility. */
+	get #effectiveViewId(): string | null {
+		return this.#viewId || this.#moduleId || null;
+	}
+
 	#broadcastPresence(cursor?: { x: number; y: number }, selection?: string) {
 		if (this.#soloMode) return; // suppress outgoing awareness in solo mode
 
@@ -411,7 +416,7 @@ export class RStackCollabOverlay extends HTMLElement {
 			selection,
 			username: this.#localUsername,
 			color: this.#localColor,
-			viewId: this.#viewId,
+			viewId: this.#effectiveViewId,
 		});
 	}
 
@@ -619,7 +624,8 @@ export class RStackCollabOverlay extends HTMLElement {
 			if (peer.module) ctxParts.push(peer.module);
 			if (peer.context) ctxParts.push(peer.context);
 			const ctxStr = ctxParts.join(' · ');
-			const differentView = !!(this.#viewId && peer.viewId && this.#viewId !== peer.viewId);
+			const localView = this.#effectiveViewId;
+			const differentView = !!((localView || peer.viewId) && localView !== peer.viewId);
 			fragments.push(`
 				<div class="people-row${differentView ? ' different-view' : ''}">
 					<span class="dot" style="background:${peer.color}"></span>
@@ -778,10 +784,12 @@ export class RStackCollabOverlay extends HTMLElement {
 		const now = Date.now();
 		const fragments: string[] = [];
 
-		for (const peer of this.#peers.values()) {
+		// Deduplicate by username — only show the most recent cursor per user
+		const localView = this.#effectiveViewId;
+		for (const peer of this.#uniquePeers()) {
 			if (!peer.cursor) continue;
-			// Skip peers viewing a different sub-document (e.g. different note in rDocs)
-			if (this.#viewId && peer.viewId && this.#viewId !== peer.viewId) continue;
+			// Only show cursors for peers on the same page/view
+			if ((localView || peer.viewId) && localView !== peer.viewId) continue;
 			const age = now - peer.lastSeen;
 			const opacity = age > 5000 ? 0.3 : 1;
 
@@ -819,10 +827,11 @@ export class RStackCollabOverlay extends HTMLElement {
 		// Remove all existing focus rings from the document
 		document.querySelectorAll('.rstack-collab-focus-ring').forEach(el => el.remove());
 
-		for (const peer of this.#peers.values()) {
+		const localView = this.#effectiveViewId;
+		for (const peer of this.#uniquePeers()) {
 			if (!peer.selection) continue;
-			// Skip peers viewing a different sub-document
-			if (this.#viewId && peer.viewId && this.#viewId !== peer.viewId) continue;
+			// Only show focus rings for peers on the same page/view
+			if ((localView || peer.viewId) && localView !== peer.viewId) continue;
 			const target = this.#findCollabEl(peer.selection);
 			if (!target) continue;