fix: add || true to bashrc snippet to prevent command chain failure

When ~/.mux/bashrc doesn't exist, [ -f ... ] returns non-zero.
In SSH runtime, commands are joined with &&, so a non-zero return
breaks the entire command chain.

The pattern '[ -f file ] && . file || true' ensures:
- If file exists: source it normally
- If file doesn't exist: || true returns 0, chain continues

Author: ammar-agent

src/common/constants/paths.test.ts

@@ -22,13 +22,14 @@ describe("getMuxBashrcSourceSnippet", () => {
     expect(snippet).toContain("$HOME/");
   });
 
-  it("should silently skip if file doesn't exist", () => {
+  it("should silently skip if file doesn't exist and return success", () => {
     const snippet = getMuxBashrcSourceSnippet();
 
-    // Should use && to only source if test succeeds (file exists)
-    // This pattern: [ -f file ] && . file
-    // - If file doesn't exist, [ -f file ] returns 1, && short-circuits, no error
-    // - If file exists, [ -f file ] returns 0, && continues to source file
+    // Should use the pattern: [ -f file ] && . file || true
+    // - If file doesn't exist, [ -f file ] returns 1, && short-circuits, || true returns 0
+    // - If file exists, [ -f file ] returns 0, && sources file, || is skipped
+    // The || true is critical for SSH runtime where commands are joined with &&
     expect(snippet).toContain("] && .");
+    expect(snippet).toContain("|| true");
   });
 });

src/common/constants/paths.ts

@@ -137,6 +137,9 @@ export const MUX_BASHRC_FILENAME = "bashrc";
  */
 export function getMuxBashrcSourceSnippet(): string {
   // Use $HOME/.mux/bashrc to work on both local and SSH runtimes
-  // The -f test and source are combined to silently skip if file doesn't exist
-  return `[ -f "$HOME/.mux/bashrc" ] && . "$HOME/.mux/bashrc"`;
+  // The pattern `[ -f file ] && . file || true` ensures:
+  // 1. If file exists: source it, return its exit status (typically 0)
+  // 2. If file doesn't exist: [ -f ] returns 1, && short-circuits, || true returns 0
+  // This is critical for SSH runtime where commands are joined with &&
+  return `[ -f "$HOME/.mux/bashrc" ] && . "$HOME/.mux/bashrc" || true`;
 }