Add profile picker to cookie import UI

[ngurney]

Problem

Chromium-based browsers support multiple profiles, each with its own cookie store. The cookie picker always read from the `Default` profile, making it impossible to import cookies from other profiles (e.g. a work or personal Arc/Chrome profile where your dev app session lives).

Solution

After selecting a browser, the picker now loads its available profiles and shows a row of profile pills. Switching profiles reloads the domain list. The selected profile is sent with import requests.

Profile display names are read from each profile's `Preferences` JSON (the same name shown in the browser's profile switcher), falling back to the directory name if unavailable.

Changes

• `cookie-import-browser.ts` — new `listProfiles(browser)` scans for `Default` + `Profile N` subdirs that have a `Cookies` file, reads display names from `Preferences`, returns `ProfileInfo[]` sorted Default-first
• `cookie-picker-routes.ts` — new `GET /cookie-picker/profiles?browser=` endpoint; `profile` param threaded through `/domains` and `/import` routes
• `cookie-picker-ui.ts` — profile pills row rendered between browser selector and search (hidden when only one profile exists); pills show display names, send directory ids in requests
• `write-commands.ts` — `--profile` flag added to direct CLI import: `cookie-import-browser arc --domain localhost --profile "Profile 1"`

Behaviour

• Single-profile browsers: profile pills row is hidden, no change in UX
• Multi-profile browsers: profile pills appear below the browser selector showing each profile's display name; first profile is auto-selected

🤖 Generated with Claude Code

[ngurney]

Closing in favour of #65 which covers the same ground and adds an Import All button + fixes findInstalledBrowsers() detection.

One thing worth adding to #65: for Chrome profiles signed into a Google account, profile.name gives generic names like "Person 2". Checking account_info[0].email first gives much more useful labels (e.g. "nick@example.com"). Simple addition to readProfileName / wherever you read the display name:

const email = prefs?.account_info?.[0]?.email;
if (email) return email;
return prefs?.profile?.name ?? null;