[FEATURE] Fleetview, allow renaming of projects

### Preflight Checklist

- [x] I have searched [existing requests](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20label%3Aenhancement) and this feature hasn't been requested yet
- [x] This is a single feature request (not multiple features)

### Problem Statement

When in Claude Agent Fleetview screen, in project view, groups of agent's are divided by path, this would be much more useful if they could be labelled.

Now
```
~/dev/foo/project1
∙ Issue 449 Stopped · stopped from session 1h

~/dev/foo
✻ housekeeping maintenance Done · Draft PR https://github.com/foo/pull/22 #14 16h

~/dev/foo/project2
✻ 22-598 Done · AB#598→Resolved, AB#597 AC3 posted, handover.md updated… #22 7m
```

### Proposed Solution

Use the current ctrl+r to rename command, but extend it to apply to projects.

Proposed
```
foo
✻ housekeeping maintenance Done · Draft PR https://github.com/foo/pull/22 #14 16h

project1
∙ Issue 449 Stopped · stopped from session 1h

project2
✻ 22-598 Done · AB#598→Resolved, AB#597 AC3 posted, handover.md updated… #22 7m
```

### Alternative Solutions

_No response_

### Priority

Medium - Would be very helpful

### Feature Category

CLI commands and flags

### Use Case Example

_No response_

### Additional Context

_No response_

Start by locating the Fleetview project grouping and the existing ctrl+r rename command. Trace how project paths are displayed and how rename state is stored, then verify that renamed labels appear in project view while the existing session rename behavior still works.

Written by the indexing model from the issue text.