feat: interactive CLI approval flow and trusted session override #350

Summary
Add a real approval round-trip for interactive CLI sessions and a session-scoped trusted-local override, while keeping strict defaults for non-interactive and remote execution.

Scope

• Implement actionable yes/no approvals in interactive CLI mode
• Add a session-scoped trust override for local interactive CLI only
• Do not weaken remote/chat/gateway defaults
• Update docs and tests

Motivation
Current approval prompts are returned as plain text and stop execution, which is safe but clunky. Local interactive sessions need a real approval UX without broad auto-approval for all CLI invocations.