fix: arr log/stacks now excludes immutable remote-tracking branches

The revset `trunk()..heads(trunk()..)` was including immutable
remote-tracking branches that clutter the log. Now uses
`mutable() & trunk()..heads(trunk()..)` to show only mutable changes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: jonathanlab

packages/core/src/jj.ts

@@ -597,8 +597,10 @@ export class JJ {
   }
 
   async getStacks(): Promise<Result<StackInfo[]>> {
-    // Get all changes from trunk to all heads
-    const allChanges = await this.list({ revset: "trunk()..heads(trunk()..)" });
+    // Get all MUTABLE changes from trunk to all heads (excludes remote-tracking branches)
+    const allChanges = await this.list({
+      revset: "mutable() & trunk()..heads(trunk()..)",
+    });
     if (!allChanges.ok) return allChanges;
 
     // Get trunk ID
@@ -675,8 +677,10 @@ export class JJ {
   }
 
   async getLog(): Promise<Result<LogResult>> {
-    // Get ALL changes from trunk to all heads (all stacks)
-    const listResult = await this.list({ revset: "trunk()..heads(trunk()..)" });
+    // Get all MUTABLE changes from trunk to all heads (excludes remote-tracking branches)
+    const listResult = await this.list({
+      revset: "mutable() & trunk()..heads(trunk()..)",
+    });
     if (!listResult.ok) return listResult;
 
     const statusResult = await this.status();