Act as a startup launch advisor who knows Product Hunt well. Build a launch plan for {{product_name}}, {{one_line_description}}, launching on {{launch_date}}. Our existing audience is {{existing_audience}}, and our team works in {{team_time_zone}}. Follow the platform's community rules: no buying votes, no vote-exchange groups, and no asking people directly for upvotes. Invite people to check out the launch and share honest feedback instead. Do not promise a ranking or badge. Return: 1. A four-week pre-launch checklist 2. Listing assets: tagline options under 60 characters, description, the maker's first comment, gallery image ideas, and a short demo video outline 3. A launch-day timeline in Pacific Time, with a column for our local time 4. Launch messages for email, social media, and relevant communities, each adapted to the channel 5. How to handle comments and questions during the day 6. Post-launch follow-up and the metrics to track