feat: Add Edit tool to auto-approve permissions with opt-out documentation

## Context
Direct quote from user:
> "Edit file yes I would need to of course approve of this in order for close issue command to work independently or else how would it make changes. that being said this one is more nuanced since i do prefer having the ability to accept / reject when truly 'vibe coding' although perhaps thats a habit i shouldnt be engaging in as much anymore as we look towards taking a less edit by edit and more pr by pr based and issue scope based management approach therefore i would lean towards implementing this without second thought and making it easy to turn off for example write some documentation saying how to manually turn it off for those moments when you really want more control and are more hands on keyboard"

## Decision
Add `"Edit"` to auto-approve permissions to enable autonomous `/close-issue` workflow.

## Nuance
This is different from read-only permissions because:
- Edit directly modifies files
- Sometimes want manual control during "vibe coding" sessions
- But moving toward PR-by-PR management, not edit-by-edit

## Implementation
1. Add `"Edit"` to `.claude/settings.local.json` permissions
2. Document how to temporarily disable for hands-on sessions:
```json
// To disable Edit auto-approve for vibe coding:
// Comment out or remove this line:
"Edit",
```

## Philosophy Shift
Moving from:
- Edit-by-edit approval (micromanagement)
- Hands always on keyboard

To:
- Issue-scope management
- PR-based workflows
- Trust the agent within bounded contexts

Related: #593, #600, #603 (permissions work)
Principle: selective-optimization

Start by checking .claude/settings.local.json and the related permissions work in issues #593, #600, and #603. Add the Edit permission and document how to comment out or remove it for manual-control sessions; done means the autonomous close-issue workflow is enabled and the opt-out instructions are present.

Written by the indexing model from the issue text.