refactor: large codebase cleanup - consolidate schemas, migrate to Drizzle ORM, extract frontend components, modernize Docker builds

- Consolidate all DB schema definitions into packages/shared as single source of truth
- Migrate backend from raw SQL to Drizzle ORM across all modules
- Extract frontend inline UI into separate component files
- Refactor discord-gateway circuitBreaker into conversationState + moderationState
- Convert messageStore to Proxy singleton pattern
- Add validateBody/validateQuery middleware + Zod schemas for API endpoints
- Modernize Docker builds with multi-stage + pnpm deploy
- Migrate CI/CD from deployment to image-based pipeline
- Remove 60+ unused/dead files (~15K lines)
- Update color scheme from sky-blue to teal-cyan
- Move DB connection management to @bete/shared/database

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

services/backend/src/shared/config/index.ts

@@ -2,4 +2,3 @@ import "dotenv/config";
 import { config as sharedConfig } from "@bete/shared/config";
 
 export const config = sharedConfig;
-export type Config = typeof config;

services/backend/src/shared/database/index.ts

@@ -1,67 +1,39 @@
+import {
+  closeDatabase as sharedCloseDb,
+  getDatabase as sharedGetDb,
+  getPool as sharedGetPool,
+  initializeDatabase as sharedInit,
+} from "@bete/shared/database/init";
 import { createChildLogger } from "@bete/shared/logger";
-import { drizzle } from "drizzle-orm/node-postgres";
-import { Pool } from "pg";
 import { config } from "../config/index.js";
 
 const logger = createChildLogger("database");
 
-let pool: Pool | null = null;
-let db: ReturnType<typeof drizzle> | null = null;
+const dbConfig = {
+  DATABASE_URL: config.DATABASE_URL,
+  POSTGRES_HOST: config.POSTGRES_HOST as string | undefined,
+  POSTGRES_PORT: config.POSTGRES_PORT,
+  POSTGRES_USER: config.POSTGRES_USER as string | undefined,
+  POSTGRES_PASSWORD: config.POSTGRES_PASSWORD as string | undefined,
+  POSTGRES_DB: config.POSTGRES_DB as string | undefined,
+  POSTGRES_POOL_MIN: config.POSTGRES_POOL_MIN,
+  POSTGRES_POOL_MAX: config.POSTGRES_POOL_MAX,
+};
 
 export async function initializeDatabase() {
-  if (db) {
-    logger.warn("Database already initialized");
-    return db;
-  }
-
-  const databaseUrl =
-    config.DATABASE_URL ||
-    `postgresql://${config.POSTGRES_USER}${config.POSTGRES_PASSWORD ? `:${config.POSTGRES_PASSWORD}` : ""}@${config.POSTGRES_HOST}:${config.POSTGRES_PORT}/${config.POSTGRES_DB}`;
-
-  pool = new Pool({
-    connectionString: databaseUrl,
-  });
-
-  pool.on("error", (err) => {
-    logger.error({ err }, "Unexpected error on idle client");
-  });
-
-  try {
-    const client = await pool.connect();
-    client.release();
-    logger.info("Database connection successful");
-  } catch (err) {
-    logger.error({ err }, "Failed to connect to database");
-    throw err;
-  }
-
-  db = drizzle(pool);
-  return db;
+  logger.info("Initializing database");
+  return sharedInit(dbConfig);
 }
 
 export function getDatabase() {
-  if (!db) {
-    throw new Error(
-      "Database not initialized. Call initializeDatabase() first.",
-    );
-  }
-  return db;
+  return sharedGetDb();
 }
 
 export function getPool() {
-  if (!pool) {
-    throw new Error(
-      "Database not initialized. Call initializeDatabase() first.",
-    );
-  }
-  return pool;
+  return sharedGetPool();
 }
 
 export async function closeDatabase() {
-  if (pool) {
-    await pool.end();
-    pool = null;
-    db = null;
-    logger.info("Database connection closed");
-  }
+  logger.info("Closing database");
+  return sharedCloseDb();
 }

services/backend/src/shared/middlewares/index.ts

@@ -1,6 +1,7 @@
 import { AppError, ValidationError } from "@bete/shared/errors";
 import { createChildLogger } from "@bete/shared/logger";
 import type { NextFunction, Request, Response } from "express";
+import type { ZodSchema } from "zod";
 
 const logger = createChildLogger("middleware");
 
@@ -90,3 +91,49 @@ export function requireParam(
   }
   return value;
 }
+
+/**
+ * Express middleware that validates `req.body` against a Zod schema.
+ * On success, replaces `req.body` with the parsed (and defaulted) value.
+ * On failure, responds with 400 and the Zod validation errors.
+ */
+export function validateBody<T>(schema: ZodSchema<T>) {
+  return (req: Request, res: Response, next: NextFunction) => {
+    const result = schema.safeParse(req.body);
+    if (!result.success) {
+      res.status(400).json({
+        error: "VALIDATION_ERROR",
+        message: "Request body validation failed",
+        details: result.error.flatten().fieldErrors,
+      });
+      return;
+    }
+    req.body = result.data;
+    next();
+  };
+}
+
+/**
+ * Express middleware that validates `req.query` against a Zod schema.
+ * On success, replaces `req.query` with the parsed (and defaulted) value.
+ * On failure, responds with 400 and the Zod validation errors.
+ */
+export function validateQuery<T>(schema: ZodSchema<T>) {
+  return (req: Request, res: Response, next: NextFunction) => {
+    const result = schema.safeParse(req.query);
+    if (!result.success) {
+      res.status(400).json({
+        error: "VALIDATION_ERROR",
+        message: "Query parameter validation failed",
+        details: result.error.flatten().fieldErrors,
+      });
+      return;
+    }
+    // Note: Express req.query is typed as ParsedQs — we attach parsed data
+    // alongside it via a custom property. For route handlers that read req.query
+    // directly, the middleware won't change the type; handlers should opt in by
+    // reading from the validated result or by using the schema's output type.
+    (req as Request & { validatedQuery: T }).validatedQuery = result.data;
+    next();
+  };
+}