Mastra Connect Adds Per-Request Tool Policies

This is a small API change with outsized security value: tool availability and approval can now follow caller context instead of being frozen at agent construction.

• –Viewers can receive read-only tools while operators retain mutation capabilities.
• –Sensitive actions can require approval only for selected roles or tool patterns.
• –Resolver caching supports bounded role variants, but developers should avoid deriving options from unbounded per-user data.
• –Connect still handles provider credentials and proxying; tool filters complement, rather than replace, provider-level permissions.