ciaranbor 6172617b00 add env override to macos app (#1869) ...

## Motivation

- Let users pass/override arbitrary exo env vars from the macOS app
without a code change.

## Changes

- `ExoProcessController.swift`: `CustomEnvironmentVariable` struct +
`@Published` list persisted to `UserDefaults`, injected into the child
process after built-ins.
- `SettingsView.swift`: new **Environment** tab with add/remove rows,
trim + dedup on save, and a POSIX name validator with a warning badge.

## Why It Works

- Custom vars applied last in `makeEnvironment`, so overriding a
built-in works with no special-casing.

## Test Plan

### Manual Testing

- Set `EXO_LIBP2P_NAMESPACE` via the new UI; confirmed override in
`~/.exo/exo_log/exo.log`.

2026-04-10 17:39:55 +01:00

..

EXO

add env override to macos app (#1869)

2026-04-10 17:39:55 +01:00