Show the current working/project directory in the Orbit UI

## What happened

A beta tester repeatedly started work against the wrong project directory without realizing it ("working in the wrong directory AGAIN"). There's no visible indication in the Orbit UI of which directory / project the agent is currently operating in, so it's easy to sit down and start a session pointed at the wrong place.

## Context

In this session the agent ran from one analyses directory while the user expected a different project, then spent several turns trying to locate a file that lived in a different project tree entirely. A persistent, glanceable cwd/project indicator would have caught the mismatch immediately.

## Expected vs actual

- Expected: a visible, persistent indicator of the active working directory / project name (e.g. in the header or near the chat input).
- Actual: no UI cue for the current directory; users only discover the mismatch after the agent does the wrong work or fails to find expected files.

## Related

The same session also surfaced the agent reaching outside the workspace (recursive `find` over `$HOME`, then attempting reads outside the project) -- tracked separately under #224 (and the runaway-find facet under #242). This issue is strictly the **UI directory-indicator** ask.

## Sysinfo

Orbit 0.3.1 - darwin/arm64 - electron 41.2.1