refactor(db): replace DATABASE_URL with individual POSTGRES_* env vars

Eliminates duplicate configuration by building the connection URL
from POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB, POSTGRES_HOST,
and POSTGRES_PORT instead of requiring a separate DATABASE_URL.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

6 files changed, 17 insertions, 19 deletions

diff --git a/.env.example b/.env.example
index 90ff45a..6ba9628 100644
--- a/.env.example
+++ b/.env.example
@@ -1,5 +1,6 @@
 POSTGRES_USER=kioku
 POSTGRES_PASSWORD=kioku
 POSTGRES_DB=kioku
-DATABASE_URL=postgresql://kioku:kioku@kioku-db:5432/kioku
+POSTGRES_HOST=localhost
+POSTGRES_PORT=5432
 JWT_SECRET=your-secret-key-here
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f83116e..86db887 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -34,7 +34,7 @@ jobs:
         run: pnpm typecheck
 
       - name: Test
-        run: DATABASE_URL="fake" pnpm test
+        run: POSTGRES_USER=test POSTGRES_PASSWORD=test POSTGRES_DB=test POSTGRES_HOST=localhost POSTGRES_PORT=5432 pnpm test
 
       - name: Build
         run: pnpm build
diff --git a/README.md b/README.md
index 9082ab0..ce5db04 100644
--- a/README.md
+++ b/README.md
@@ -29,8 +29,6 @@ pnpm install
 
 # Copy environment variables
 cp .env.example .env
-# Edit .env for local development:
-#   DATABASE_URL=postgresql://kioku:kioku@localhost:5432/kioku
 
 # Start PostgreSQL
 docker compose up db -d
@@ -53,7 +51,8 @@ pnpm dev:client   # Frontend dev server (port 5173)
 | `POSTGRES_USER` | PostgreSQL username | `kioku` |
 | `POSTGRES_PASSWORD` | PostgreSQL password | `kioku` |
 | `POSTGRES_DB` | PostgreSQL database name | `kioku` |
-| `DATABASE_URL` | Full PostgreSQL connection string | `postgresql://kioku:kioku@localhost:5432/kioku` |
+| `POSTGRES_HOST` | PostgreSQL host | `kioku-db` |
+| `POSTGRES_PORT` | PostgreSQL port | `5432` |
 | `JWT_SECRET` | Secret key for JWT tokens (use a secure random string in production) | `your-secret-key` |
 
 ## Scripts
diff --git a/compose.yaml b/compose.yaml
index 6308342..8c89cd3 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -24,7 +24,11 @@ services:
     container_name: kioku-server
     restart: unless-stopped
     environment:
-      DATABASE_URL: ${DATABASE_URL}
+      POSTGRES_USER: ${POSTGRES_USER}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_DB: ${POSTGRES_DB}
+      POSTGRES_HOST: kioku-db
+      POSTGRES_PORT: 5432
       JWT_SECRET: ${JWT_SECRET}
       NODE_ENV: production
     expose:
diff --git a/drizzle.config.ts b/drizzle.config.ts
index 6fe73ec..0520eb6 100644
--- a/drizzle.config.ts
+++ b/drizzle.config.ts
@@ -1,15 +1,12 @@
 import { defineConfig } from "drizzle-kit";
 
-const databaseUrl = process.env.DATABASE_URL;
-if (!databaseUrl) {
-	throw new Error("DATABASE_URL environment variable is not set");
-}
+const { POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB, POSTGRES_HOST, POSTGRES_PORT } = process.env;
 
 export default defineConfig({
 	out: "./drizzle",
 	schema: "./src/server/db/schema.ts",
 	dialect: "postgresql",
 	dbCredentials: {
-		url: databaseUrl,
+		url: `postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}`,
 	},
 });
diff --git a/src/server/db/index.ts b/src/server/db/index.ts
index 0e69fad..4826710 100644
--- a/src/server/db/index.ts
+++ b/src/server/db/index.ts
@@ -2,15 +2,12 @@ import { drizzle } from "drizzle-orm/node-postgres";
 import * as schema from "./schema.js";
 import * as schemaCrdt from "./schema-crdt.js";
 
-const databaseUrl = process.env.DATABASE_URL;
+const { POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB, POSTGRES_HOST, POSTGRES_PORT } = process.env;
 
-if (!databaseUrl) {
-	throw new Error("DATABASE_URL environment variable is not set");
-}
-
-export const db = drizzle(databaseUrl, {
-	schema: { ...schema, ...schemaCrdt },
-});
+export const db = drizzle(
+	`postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}`,
+	{ schema: { ...schema, ...schemaCrdt } },
+);
 
 export * from "./schema.js";
 export * from "./schema-crdt.js";