Unify bot tables into single bots + bot_triggers schema

Replace 8 provider-specific tables (discord_bots, telegram_bots,
whatsapp_accounts, slack_bots and their trigger tables) with 2 unified
tables using provider discriminator and JSON metadata columns, matching
the existing integrations table pattern.

- Add bots table with provider, encrypted_token, metadata, encrypted_metadata
- Add bot_triggers table with provider, metadata JSON for trigger config
- Unified API route at /:orgId/bots with ?provider= filter
- Unified trigger endpoint at /:workflowId/bot-trigger
- Unified bot-service.ts frontend service with backward-compatible aliases
- Webhook handlers updated to parse metadata JSON for provider-specific fields

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bchapuis

apps/api/src/db/migrations/0051_unify_bots.sql

@@ -0,0 +1,47 @@
+-- Drop old bot and trigger tables
+DROP TABLE IF EXISTS `discord_triggers`;
+DROP TABLE IF EXISTS `telegram_triggers`;
+DROP TABLE IF EXISTS `whatsapp_triggers`;
+DROP TABLE IF EXISTS `slack_triggers`;
+DROP TABLE IF EXISTS `discord_bots`;
+DROP TABLE IF EXISTS `telegram_bots`;
+DROP TABLE IF EXISTS `whatsapp_accounts`;
+DROP TABLE IF EXISTS `slack_bots`;
+
+-- Unified Bots table
+CREATE TABLE IF NOT EXISTS `bots` (
+  `id` text PRIMARY KEY NOT NULL,
+  `name` text NOT NULL,
+  `provider` text NOT NULL,
+  `encrypted_token` text NOT NULL,
+  `token_last_four` text NOT NULL,
+  `metadata` text,
+  `encrypted_metadata` text,
+  `organization_id` text NOT NULL REFERENCES `organizations`(`id`) ON DELETE CASCADE,
+  `created_at` integer DEFAULT (unixepoch()) NOT NULL,
+  `updated_at` integer DEFAULT (unixepoch()) NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS `bots_name_idx` ON `bots` (`name`);
+CREATE INDEX IF NOT EXISTS `bots_provider_idx` ON `bots` (`provider`);
+CREATE INDEX IF NOT EXISTS `bots_organization_id_idx` ON `bots` (`organization_id`);
+CREATE INDEX IF NOT EXISTS `bots_created_at_idx` ON `bots` (`created_at`);
+
+-- Unified Bot Triggers table
+CREATE TABLE IF NOT EXISTS `bot_triggers` (
+  `workflow_id` text PRIMARY KEY NOT NULL REFERENCES `workflows`(`id`) ON DELETE CASCADE,
+  `organization_id` text NOT NULL REFERENCES `organizations`(`id`) ON DELETE CASCADE,
+  `bot_id` text REFERENCES `bots`(`id`) ON DELETE SET NULL,
+  `provider` text NOT NULL,
+  `metadata` text,
+  `active` integer NOT NULL DEFAULT 1,
+  `created_at` integer DEFAULT (unixepoch()) NOT NULL,
+  `updated_at` integer DEFAULT (unixepoch()) NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS `bot_triggers_organization_id_idx` ON `bot_triggers` (`organization_id`);
+CREATE INDEX IF NOT EXISTS `bot_triggers_bot_id_idx` ON `bot_triggers` (`bot_id`);
+CREATE INDEX IF NOT EXISTS `bot_triggers_provider_idx` ON `bot_triggers` (`provider`);
+CREATE INDEX IF NOT EXISTS `bot_triggers_active_idx` ON `bot_triggers` (`active`);
+CREATE INDEX IF NOT EXISTS `bot_triggers_created_at_idx` ON `bot_triggers` (`created_at`);
+CREATE INDEX IF NOT EXISTS `bot_triggers_updated_at_idx` ON `bot_triggers` (`updated_at`);