feat: REST API v1 + API key management + Swagger docs

**API system**
- ApiKey model: SHA-256-hashed tokens (gw_<hex>), per-family, scoped
- Migration: 20260615210000_api_keys
- src/lib/api-auth.ts: verifyApiKey(), hasScope(), generateApiKey(), prepareKey()

**V1 endpoints** (all require Bearer gw_ token):
- GET  /api/v1/babies              — list family babies (any read scope)
- GET  /api/v1/events              — query events (events:read), babyId/type/from/to/limit/offset
- POST /api/v1/events              — log event (events:write), full metadata support
- GET  /api/v1/growth              — growth logs (growth:read)
- POST /api/v1/growth              — add measurement (growth:write), weight in grams
- GET  /api/v1/summary             — today's counts + sleep + last feed (summary:read)
- GET  /api/v1/milk                — stock lots + totalMl (milk:read)

**API key management**
- GET  /api/api-keys               — list keys (session auth)
- POST /api/api-keys               — create key, returns raw token once (session auth)
- DELETE /api/api-keys/[id]        — revoke key (session auth)

**Documentation**
- GET /api/v1/openapi.json         — OpenAPI 3.0 spec (CORS open)
- GET /api-docs                    — Swagger UI (CDN, dark themed)

**Settings UI** — "Clés API" section: create key with scope checkboxes, copy token banner (shown once), revoke, link to /api-docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/api/api-keys/route.ts

@@ -0,0 +1,45 @@
+import { NextResponse } from "next/server";
+import { auth } from "@/lib/auth";
+import { prisma } from "@/lib/prisma";
+import { generateApiKey, prepareKey, API_SCOPES } from "@/lib/api-auth";
+
+export async function GET() {
+  const session = await auth();
+  if (!session?.user?.id) return NextResponse.json({ error: "Non autorisé" }, { status: 401 });
+  const familyId = (session.user as { familyId?: string }).familyId;
+  if (!familyId) return NextResponse.json({ keys: [] });
+
+  const keys = await prisma.apiKey.findMany({
+    where: { familyId },
+    orderBy: { createdAt: "desc" },
+    select: { id: true, name: true, keyPrefix: true, scopes: true, lastUsedAt: true, createdAt: true },
+  });
+
+  return NextResponse.json({ keys });
+}
+
+export async function POST(req: Request) {
+  const session = await auth();
+  if (!session?.user?.id) return NextResponse.json({ error: "Non autorisé" }, { status: 401 });
+  const familyId = (session.user as { familyId?: string }).familyId;
+  if (!familyId) return NextResponse.json({ error: "Famille introuvable" }, { status: 400 });
+
+  const body = await req.json().catch(() => ({}));
+  const { name, scopes } = body;
+
+  if (!name?.trim()) return NextResponse.json({ error: "name is required" }, { status: 400 });
+
+  const validScopes = (scopes as string[] | undefined)?.filter((s) => (API_SCOPES as readonly string[]).includes(s));
+  if (!validScopes?.length) return NextResponse.json({ error: "At least one valid scope is required" }, { status: 400 });
+
+  const token = generateApiKey();
+  const data = prepareKey(token, name.trim(), familyId, validScopes);
+
+  const key = await prisma.apiKey.create({
+    data,
+    select: { id: true, name: true, keyPrefix: true, scopes: true, createdAt: true },
+  });
+
+  // Return the raw token ONCE — it cannot be retrieved again
+  return NextResponse.json({ key, token }, { status: 201 });
+}