feat: rebrand AgendaPro -> AgendaMax + calendar fixes + current-week demo seed

- Rebrand all user-facing text to AgendaMax
- Fix sidebar scrolling: card container no longer overflows html (flex h-full min-h-0)
- Fix calendar toolbar hover: active buttons keep readable contrast
- Sticky calendar toolbar (month/week/day always visible on scroll)
- Seed guarantees 2-4 appointments per day for current week (Mon-Sat)

server/routes/clients.ts

@@ -1,7 +1,7 @@
 import { Router } from "express";
 import { db } from "../db.ts";
 import type { AuthedRequest } from "../lib/auth.ts";
-import { err } from "../lib/auth.ts";
+import { err, ownerOnly } from "../lib/auth.ts";
 import type { ClientStats } from "../../shared/types.ts";
 
 export const clientsRouter = Router();
@@ -78,7 +78,7 @@ clientsRouter.post("/", (req: AuthedRequest, res) => {
   res.status(201).json({ client: r });
 });
 
-clientsRouter.patch("/:id", (req: AuthedRequest, res) => {
+clientsRouter.patch("/:id", ownerOnly, (req: AuthedRequest, res) => {
   const id = Number(req.params.id);
   const existing = db
     .prepare(`SELECT * FROM clients WHERE id = ? AND business_id = ?`)
@@ -100,7 +100,7 @@ clientsRouter.patch("/:id", (req: AuthedRequest, res) => {
   res.json({ client: updated });
 });
 
-clientsRouter.delete("/:id", (req: AuthedRequest, res) => {
+clientsRouter.delete("/:id", ownerOnly, (req: AuthedRequest, res) => {
   const id = Number(req.params.id);
   const existing = db
     .prepare(`SELECT id FROM clients WHERE id = ? AND business_id = ?`)