🔒 Fix missing process capability check in std.notification

[Tcode-Motion]

🎯 What: Fixed a security vulnerability where external processes (powershell, msg, notify-send) were spawned in stdlib/src/notification.rs (show and alert functions) without validating if the script had Capability::Process granted.
⚠️ Risk: Scripts without process execution capabilities could bypass the sandbox policy and run arbitrary commands (via UI alerts/notifications) if they utilized the std.notification module, leading to unauthorized host execution.
🛡️ Solution: Added explicit ctx.config.capabilities.contains(&Capability::Process) checks to both the show and alert function callbacks. If the capability is denied, it returns a RuntimeError (RuntimeErrorKind::InvalidOperation). Also registered Capability::Process as a required capability for the std.notification module.

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PR created automatically by Jules for task 16110128204199656425 started by @Tcode-Motion

[google-labs-jules]

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