Add Write() deny rules for shell configs

Deny Write(~/.bashrc), Write(~/.zshrc), and Write(~/.ssh/**) to match
the existing Edit() rules for those paths. The two tools are separate —
denying Edit does not block Write.

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

settings.json

@@ -25,6 +25,9 @@
       "Edit(~/.bashrc)",
       "Edit(~/.zshrc)",
       "Edit(~/.ssh/**)",
+      "Write(~/.bashrc)",
+      "Write(~/.zshrc)",
+      "Write(~/.ssh/**)",
 
       "Read(~/.ssh/**)",
       "Read(~/.gnupg/**)",