Feature/dweb activity

[Elelan]

Extracted Dweb into separate activity
decoupled from Main App

What / Why

• Isolated Snowbird flows into their own SnowbirdActivity with a dedicated nav graph and host layout, removing cross-activity fragment navigation.
• Added Snowbird-specific success screen (SnowbirdSetupSuccessFragment) and rewired create/join flows to launch success directly without hopping through SpaceSetupActivity.
• Updated success navigation to reset the Snowbird back stack to the dashboard and ensure the toolbar/back button exits to the previous activity when on the dashboard.
• Simplified Snowbird fragments to assume a single host (SnowbirdActivity), removing fallback host checks and redundant SafeArgs handling.

Key Changes

• New SnowbirdActivity and layout; manifest entry for Snowbird.
• Snowbird nav graph now starts at the dashboard, includes the Snowbird success screen, and routes create/join → success → dashboard/share.
• SnowbirdSetupSuccessFragment uses nav ID navigation (no ActionOnlyNavDirections) and pops up to the graph root to avoid back-stack loops.
• BaseSnowbirdFragment now owns dialog/analytics lifecycle and toolbar updates for Snowbird only.