Permission prompts: show requesting agent + reasoning, not just tool name + truncated command

When running multi-agent pipelines (orchestrator → subagents, each spawning Bash/git/search calls), the permission prompt currently shows only the tool name and a truncated command string. In a pipeline where several subagents run Bash independently, this makes it hard to quickly judge whether to approve — you can't tell which agent is asking or why without digging into truncated shell text.

Requested:

1. Show the requesting agent/subagent name in the permission prompt.
2. Show a short one-line reasoning for the action (many tools like Bash already have a description field — surface it in the dialog instead of/alongside the raw command).
3. Offer scoped approval choices inline at prompt time — e.g. "Allow once" / "Allow for this session" / "Allow always for this project" / "Allow always for this agent" — rather than only the current allow-once-vs-permanent-rule split.