Support Dia and discover compatible browser cookie stores

[vznh]

Human comments

Couldn't find Dia when looking on browsers, and found a hardcoded browser list. Support auto-discover for browsers that are Firefox / Chromium / ... -based else hard-code it.

What was wrong

Browser cookie import depended on a fixed registry, leaving Dia and unlisted Chromium or Firefox browsers unavailable even when their cookie storage was compatible.

What changed

Add native Dia and Zen entries and combine the existing registry with bounded discovery of compatible stores belonging to registered web browsers. Preserve known encryption identities, exclude BB and non-browser stores, and revalidate discovered sources before import. Avoid Keychain lookups for plaintext stores and reject unsupported versioned ciphertext.

Accept opaque discovered source IDs across the desktop contract and bump HOST_DAEMON_PROTOCOL_VERSION from 216 to 217. Update CLI/SDK guide surfaces and document Linux XDG, Flatpak, Snap, and encryption limitations.

How you verified

Both human and agent verified.

• pnpm exec turbo run test --filter=@bb/desktop -- browser-import.test.ts browser-applications.test.ts desktop-browser-broker-import.test.ts — 41 tests passed after cleanup.
• pnpm exec turbo run test --filter=@bb/app -- BrowserSettingsSection.test.tsx — 6 tests passed after cleanup.
• pnpm exec turbo run typecheck --filter=@bb/desktop --filter=@bb/plugin-api-map — passed after merging main.
• pnpm exec turbo run test --filter=@bb/host-daemon-contract -- desktop-browser.test.ts — 6 tests passed after merging main.
• All 53 focused desktop, UI, and contract tests passed after merging main. Earlier focused CLI and SDK tests passed.
• Read-only macOS discovery found Dia, excluded four non-browser stores, and made zero secret reads. No real cookies were imported during that check.
• git diff --check passed.

AGENT GENERATED