backend: per-user settings store (/api/settings) + enable account deletion

- user_settings table (userId PK -> user, jsonb preferences) + migration
- GET/PUT /api/settings (requireAuth, user-scoped; zod-validated flat map)
- Better Auth user.deleteUser enabled so users can delete their own account

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/drizzle/0010_eager_hellfire_club.sql

@@ -0,0 +1,7 @@
+CREATE TABLE "user_settings" (
+	"user_id" text PRIMARY KEY NOT NULL,
+	"preferences" jsonb DEFAULT '{}'::jsonb NOT NULL,
+	"updated_at" timestamp DEFAULT now() NOT NULL
+);
+--> statement-breakpoint
+ALTER TABLE "user_settings" ADD CONSTRAINT "user_settings_user_id_user_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;

backend/drizzle/meta/_journal.json

@@ -71,6 +71,13 @@
       "when": 1781022080228,
       "tag": "0009_melted_puck",
       "breakpoints": true
+    },
+    {
+      "idx": 10,
+      "version": "7",
+      "when": 1781111039837,
+      "tag": "0010_eager_hellfire_club",
+      "breakpoints": true
     }
   ]
 }

backend/src/auth.ts

@@ -43,6 +43,14 @@ export const auth = betterAuth({
     },
   },
 
+  user: {
+    // Lets a signed-in user delete their own account from Settings. The
+    // frontend confirms with the user's password (authClient.deleteUser).
+    deleteUser: {
+      enabled: true,
+    },
+  },
+
   emailVerification: {
     sendOnSignUp: true,
     autoSignInAfterVerification: true,

backend/src/db/schema/index.ts

@@ -7,3 +7,4 @@ export * from "./tasks.js";
 export * from "./activity.js";
 export * from "./messaging.js";
 export * from "./notifications.js";
+export * from "./settings.js";

backend/src/db/schema/settings.ts

@@ -0,0 +1,20 @@
+import { jsonb, pgTable, text, timestamp } from "drizzle-orm/pg-core";
+
+import { user } from "./auth.js";
+
+// Per-user preferences (notification toggles, profile extras). One row per
+// user, keyed by the Better Auth user id; the payload is a flat JSONB map so
+// the frontend can add settings without a migration.
+export const userSettings = pgTable("user_settings", {
+  userId: text("user_id")
+    .primaryKey()
+    .references(() => user.id, { onDelete: "cascade" }),
+  preferences: jsonb("preferences")
+    .$type<Record<string, boolean | string>>()
+    .notNull()
+    .default({}),
+  updatedAt: timestamp("updated_at")
+    .defaultNow()
+    .$onUpdate(() => new Date())
+    .notNull(),
+});

backend/src/index.ts

@@ -16,6 +16,7 @@ import { notesRouter } from "./routes/notes.js";
 import { notificationsRouter } from "./routes/notifications.js";
 import { patientsRouter } from "./routes/patients.js";
 import { prescriptionsRouter } from "./routes/prescriptions.js";
+import { settingsRouter } from "./routes/settings.js";
 import { staffRouter } from "./routes/staff.js";
 import { tasksRouter } from "./routes/tasks.js";
 
@@ -64,6 +65,7 @@ app.use("/api/activity", activityRouter);
 app.use("/api/analytics", analyticsRouter);
 app.use("/api/conversations", conversationsRouter);
 app.use("/api/notifications", notificationsRouter);
+app.use("/api/settings", settingsRouter);
 
 app.use(notFound);
 app.use(errorHandler);
@@ -85,4 +87,5 @@ server.listen(env.PORT, () => {
   console.log(`  • stats:    /api/analytics`);
   console.log(`  • messages: /api/conversations  (+ Socket.io)`);
   console.log(`  • notifs:   /api/notifications`);
+  console.log(`  • settings: /api/settings`);
 });

backend/src/lib/settings-validation.ts

@@ -0,0 +1,16 @@
+import { z } from "zod";
+
+// Payload accepted by PUT /api/settings: a flat map of preference keys to
+// booleans or short strings. Capped so the JSONB column can't grow unbounded.
+export const settingsInputSchema = z.object({
+  preferences: z
+    .record(
+      z.string().min(1).max(64),
+      z.union([z.boolean(), z.string().max(500)]),
+    )
+    .refine((prefs) => Object.keys(prefs).length <= 100, {
+      message: "Too many preference keys.",
+    }),
+});
+
+export type SettingsInput = z.infer<typeof settingsInputSchema>;

backend/src/routes/settings.ts

@@ -0,0 +1,42 @@
+import { eq } from "drizzle-orm";
+import { Router } from "express";
+
+import { db } from "../db/index.js";
+import { userSettings } from "../db/schema/settings.js";
+import { settingsInputSchema } from "../lib/settings-validation.js";
+import { requireAuth } from "../middleware/auth.js";
+
+export const settingsRouter = Router();
+
+// Settings are per-user (not per-clinic), so only authentication is required —
+// no active organization or RBAC permission.
+settingsRouter.use(requireAuth);
+
+settingsRouter.get("/", async (req, res, next) => {
+  try {
+    const rows = await db
+      .select({ preferences: userSettings.preferences })
+      .from(userSettings)
+      .where(eq(userSettings.userId, req.user!.id))
+      .limit(1);
+    res.json({ preferences: rows[0]?.preferences ?? {} });
+  } catch (err) {
+    next(err);
+  }
+});
+
+settingsRouter.put("/", async (req, res, next) => {
+  try {
+    const { preferences } = settingsInputSchema.parse(req.body);
+    await db
+      .insert(userSettings)
+      .values({ userId: req.user!.id, preferences })
+      .onConflictDoUpdate({
+        target: userSettings.userId,
+        set: { preferences, updatedAt: new Date() },
+      });
+    res.json({ preferences });
+  } catch (err) {
+    next(err);
+  }
+});