[kasnder]

Research mode (log_logcat=true) disables tracker blocking, even when Strict mode and saved blocking rules are selected. In #968, this made the allowed-connection statistics appear to contradict the configured “Blocked” labels. The existing short toast was easy to miss.

Show a persistent notice above the Timeline, Apps, and VPN tabs while log_logcat is enabled: “Research mode is on. Tracker blocking is disabled. Tap to change settings.” Tapping opens Settings. The notice updates when the preference changes and disappears when Research is disabled. The Research preference description now explicitly states that blocking is disabled.

The notice follows log_logcat, independently of sni_enabled: enabling SNI alone does not show it, and imported settings with Research enabled but SNI disabled still do. Tracker-blocking behaviour is unchanged.

Validation:

• 10 focused ActivityMain tests pass, covering the independent settings, visibility, placement outside tab content, and Settings navigation.
• Android lint passes with 0 errors.
• Rendered the notice at 320dp and inspected wrapping and spacing.
• Not tested on a physical device.

This is a standalone UI change based on current master; it does not depend on #982.