Markdown: ordered lists always render from 1 — <ol start> is dropped

### What happens

An ordered list that starts at any number other than 1 renders starting from 1.

A chat message whose entire content is `42.` displays as `1.` — which is how I hit this: an agent answered a question with `42.`, and the channel showed `1.`, so the agent appeared to have given the wrong answer. The stored event content is `"42."`; only the rendering differs.

### Repro

Send a message containing:

```
42. answer
```

**Expected:** `42. answer` (CommonMark: an ordered list's first item sets the list's start number)
**Actual:** `1. answer`

### Cause

`desktop/src/shared/ui/markdown.tsx:1546` destructures only `children`, so the `start` prop that `react-markdown` supplies is dropped:

```tsx
ol: ({ children }) => (

{children}

),
```

With no `start` attribute, the browser numbers from 1.

`li` on the line above has the same shape, so an explicit `value` on a list item is dropped for the same reason:

```tsx
li: ({ children }) =>

{children}

,
```

Other components in the same file (for example `code` at :1439) already spread `...props`, so this looks like an oversight rather than a deliberate choice.

### Suggested fix

```tsx
li: ({ children, ...props }) => (

{children}

),
ol: ({ children, ...props }) => (

{children}

),
```

### Environment

- `react-markdown` ^10.1.0, `remark-gfm` ^4.0.1

### Note

Agents are told to use GitHub-flavored Markdown (`crates/buzz-acp/src/base_prompt.md`), so any agent replying with a bare numeric answer hits this and looks like it answered incorrectly.