Design the Permission Approval UX

PROJECT CONTEXT:
My agent asks permission constantly, users stop reading and click yes to everything - the safety layer trained them out of safety. The leading agent UX pattern is diff-first approvals, risk-proportional friction, and scoped grants.

GOAL:
Rebuild the approval experience: informative diff-first prompts, risk-tiered presentation, scoped grant options, and measured approval fatigue.

REQUIREMENTS:
- File-change approvals rendered as diffs, not descriptions
- Command approvals showing the exact command, cwd, and a plain-language risk note
- Risk-proportional presentation: routine asks are compact, dangerous asks are unmissable
- Grant scoping in the prompt: once / session / this-directory choices
- Fatigue metrics: approvals per task and time-to-decision tracked

CONSTRAINTS:
- The approval prompt must contain everything needed to decide - no digging
- Dangerous approvals must not be visually confusable with routine ones

DEFINITION OF DONE:
- An edit approval shows the actual diff with additions/deletions highlighted
- A dangerous command approval is visually distinct and states blast radius
- Scoped grants reduce repeat prompts measurably within a session
- Approvals-per-task drops after the redesign without loosening the rules

COMMON FAILURES TO AVOID:
- Approval prompts that say 'Agent wants to edit file.js - Allow?' with no diff
- Every ask styled identically, so rm approval looks like ls approval
- No session grants, generating twenty prompts for twenty edits of one file
- Unmeasured fatigue, discovered only when users disable safety wholesale