Pick sessions (frontend), roadmap and handover docs

Event wizard: how people book (whole course / pick sessions), capacity
per session and per-option session mode. Session picker on the public
registration page, Manual registration and the kiosk; at the door points
to Manual registration. Register, tickets and My Events handle picked
sessions. Adds docs/ROADMAP-v2.md and docs/HANDOVER.md so work can carry
on from another machine, and a pick-sessions e2e test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

playwright.config.ts

@@ -36,7 +36,7 @@ export default defineConfig({
       cwd: "backend",
       url: `http://localhost:${API_PORT}/api/settings/needs-setup`,
       timeout: 180_000,
-      reuseExistingServer: false,
+      reuseExistingServer: !ci,
       stdout: "ignore",
       stderr: "pipe",
       env: {
@@ -56,7 +56,7 @@ export default defineConfig({
       cwd: "frontend",
       url: `http://localhost:${WEB_PORT}`,
       timeout: 600_000,
-      reuseExistingServer: false,
+      reuseExistingServer: !ci,
       stdout: "ignore",
       stderr: "pipe",
       env: {