feat: add payout options (Stripe + Tremendous)

[TheDanniCraft]

This pull request introduces major enhancements to the payout system, including new database schema changes to support multiple payout methods (such as Stripe and Tremendous), as well as the addition of automated cron jobs for promoting conversions and synchronizing payout statuses. It also updates Docker and documentation to support these new features, making the payout process more robust and automated.

Database schema changes for payouts:

• Added a new payouts table to track partner payouts, supporting multiple payout methods (manual, Stripe customer balance, Tremendous), payout statuses, and related transaction/order IDs. (database/0005-payout-methods.sql, database/deploy.sql) [1] [2]
• Linked conversions to payouts by adding payout_id and failure tracking fields, and created appropriate indexes and foreign keys for efficient queries and referential integrity. (database/0005-payout-methods.sql, database/deploy.sql) [1] [2] [3]
• Added stripe_customer_id to the partners table and tremendous_campaign_id to the programs table to support new payout flows and campaign selection. (database/0005-payout-methods.sql, database/deploy.sql) [1] [2] [3]
• Updated default values and seeded new payout-related settings for minimum payout amounts and enabled payout methods. (database/0005-payout-methods.sql, database/deploy.sql) [1] [2]
• Set the default reward_days for new programs to 7. (database/0005-payout-methods.sql, database/deploy.sql) [1] [2]

Automated payout and conversion cron jobs:

• Added environment variables and Docker support to enable/disable and schedule cron jobs for promoting matured conversions and syncing Tremendous payout statuses. (docker/.env_example, docker/docker-compose.yml, docker/entrypoint.sh, docker/Dockerfile) [1] [2] [3] [4] [5]
• Documented the new cron jobs and their configuration in both the Docker and main project README files. (docker/README_DOCKER.md, readme.md) [1] [2]

Application routes for new payout features:

• Added new routes for partners to link/unlink their payout accounts, request payouts, and receive webhook notifications for Tremendous. (public/index.php) [1] [2]

[TheDanniCraft]

@dfgonzalez I think its ready for review now