[lauridskern]

Adds basic product analytics so we can see how many installations use Mobile Dev and which tools they use most.

What's tracked

• Session Started: once each time a host connects. Mixpanel's unique-user count on this event gives installations per host.
• Tool Called: the tool name and a success or error outcome. Tools that poll or send input many times a second are skipped.
• Each event also carries host, plugin_version, os, a timestamp, an insert ID, and the existing installation ID as distinct_id.

Privacy

• Sent from the server only, through instrumentProductAnalytics in packages/core/src/analytics.ts, which wraps the tools/call handler. Requests go to api-eu.mixpanel.com/track?ip=0&verbose=1, so no IPs are stored and no locations are derived; verbose=1 makes Mixpanel report rejected batches, which analytics.flush counts as failed.
• No user profiles, tool arguments or results, device details, paths or account data.
• Release builds only. MOBILE_DEV_TELEMETRY=off turns analytics off along with Sentry. MOBILE_DEV_ANALYTICS=off or DO_NOT_TRACK=1 turns off only analytics.
• PRIVACY.md and the website privacy page now cover what Mixpanel receives, Mixpanel as a recipient, retention and the opt-out. docs/telemetry.md has a new "Product analytics" section.

Telemetry

• New Sentry counter analytics.flush by outcome, so Mixpanel delivery failures show up. Existing Sentry coverage is unchanged.

Tests

• New packages/core/test/analytics.test.ts passes, along with the existing telemetry tests.
• npm test: 962 passed, 5 failed. All 5 are in agent-device-catalog.test.ts and fail the same way on main.

Before release

• Confirm the Mixpanel project uses EU data residency. If it doesn't, the EU endpoint rejects events.
• Configure or confirm the 24-month retention stated in the policy.
• Make sure a DPA with Mixpanel is in place.
• Legal check: analytics is on by default with an opt-out, on the basis of legitimate interest, like the current Sentry usage counters. A strict reading of ePrivacy could require asking for consent first.