feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

f_scripts/install_memberships.sql

@@ -0,0 +1,42 @@
+-- Membership tiers per channel
+CREATE TABLE IF NOT EXISTS `db_membership_tiers` (
+  `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
+  `usr_id` INT UNSIGNED NOT NULL,
+  `tier_id` INT UNSIGNED NOT NULL,
+  `name` VARCHAR(120) NOT NULL,
+  `price_cents` INT UNSIGNED NOT NULL DEFAULT 0,
+  `currency` CHAR(3) NOT NULL DEFAULT 'USD',
+  `perks_json` TEXT NULL,
+  `badge_key` VARCHAR(64) NULL,
+  `chat_access` TINYINT(1) NOT NULL DEFAULT 1,
+  `active` TINYINT(1) NOT NULL DEFAULT 1,
+  PRIMARY KEY (`id`),
+  KEY `usr_tier` (`usr_id`,`tier_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+-- User <> Channel membership relationships
+CREATE TABLE IF NOT EXISTS `db_user_memberships` (
+  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+  `subscriber_usr_id` INT UNSIGNED NOT NULL,
+  `channel_usr_id` INT UNSIGNED NOT NULL,
+  `tier_id` INT UNSIGNED NOT NULL,
+  `status` ENUM('active','canceled','expired','past_due') NOT NULL DEFAULT 'active',
+  `provider` VARCHAR(24) NULL,
+  `provider_ref` VARCHAR(128) NULL,
+  `started_at` DATETIME NOT NULL,
+  `expires_at` DATETIME NULL,
+  PRIMARY KEY (`id`),
+  KEY `sub_chan` (`subscriber_usr_id`,`channel_usr_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+-- Optional file access rules
+CREATE TABLE IF NOT EXISTS `db_file_access_rules` (
+  `id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
+  `file_key` VARCHAR(32) NOT NULL,
+  `type` ENUM('video','live','short','image','audio','doc','blog') NOT NULL DEFAULT 'video',
+  `channel_usr_id` INT UNSIGNED NOT NULL,
+  `required_tier_id` INT UNSIGNED NOT NULL,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `u_file` (`file_key`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+