feat(studio): diagnostics polish

[pbertsch]

Summary

Three small frontend improvements that make Studio less mysterious when things go wrong. v0.7.1 PR 3 of 3.

Changes

1. `enrichError(msg)` — actionable hints in error toasts

Connection error messages today are honest but bare ("iproxy not found"). The new helper appends a one-line fix:

Pattern matched	Hint appended
`iproxy`	`Fix: brew install libimobiledevice`
`idevicesyslog`	`Fix: brew install libimobiledevice (idevicesyslog ships with it)`
`adb` + `not found`	`Fix: install Android SDK platform-tools and ensure adb is on your PATH`
`token` + `(not found|timeout)`	`Fix: confirm your Flutter app is running with --dart-define=PROBE_AGENT=true`
`PROBE_AGENT`	`Fix: rebuild your Flutter app with --dart-define=PROBE_AGENT=true`
`refused|reset by peer|EOF`	`Fix: the agent process likely isn't running. Start your Flutter app and try again.`

Wired into both `Connect` and `ConnectWiFi` error paths.

2. Status indicator tooltip

The dot + status text now carry a `title` showing device id, transport (USB / WiFi), and last error. Hover to see the full picture without consuming toolbar real estate.

3. Inspector search box

Text input in the inspector pane title scrolls the `

` to the first line containing the query. `MutationObserver` re-anchors the scroll on each live device-stream frame, so the matched line doesn't jump back to the top when the tree refreshes.

Test plan

 `tsc --noEmit` clean
 `go build ./...` + `go vet` clean (no Go changes — purely frontend)
 Manual: enrichError — disconnect a USB cable mid-connect, verify the toast includes a fix hint
 Manual: tooltip — hover the status dot after connecting, verify it shows device id + transport
 Manual: inspector search — connect, type "Scaffold" in the search box, verify the `
` scrolls to the first occurrence and stays anchored across live updates