chore: settle product naming across app, widget and deployments

One word everywhere: ReplyPier in UI copy, package and image names, the
replypier.site domains (app/api/docs/help), REPLYPIER_* settings and the
--rp-* design tokens.

- public widget API is window.ReplyPier with replypierId / replypierBaseUrl /
  replypierConfig / replypierToken, loader at webclient/replypier.min.js;
  both bundles rebuilt from source
- NOTICE, llms.txt, CONTRIBUTING, HELP_CENTER_INFRA and the demo runtime
  config rewritten; the demo config ships no third-party keys
- migration adds the ReplyPier managed model value to the AI model enum
- local compose project, database, role, volume and Docker network carry the
  same name

e2e/specs/a11y/a11y.spec.ts

@@ -11,14 +11,14 @@ test.describe('accessibility', () => {
     await expectNoNewA11yViolations(anonymousPage, 'login')
   })
 
-  // The dashboard is dark unless the user picks light (stored as cm-theme); both are checked.
+  // The dashboard is dark unless the user picks light (stored as rp-theme); both are checked.
   for (const scheme of ['dark', 'light'] as const) {
     const suffix = scheme === 'dark' ? '' : '-light'
 
     test(`dashboard screens, ${scheme} theme @a11y`, async ({ page, agent, agentsPage, aiConfigPage, ticketsPage, peoplePage }) => {
       // An agent of its own, so the agents screen is the list (with a card to check), not first-run setup.
       expect(agent.id).toBeTruthy()
-      await page.addInitScript((theme) => localStorage.setItem('cm-theme', theme), scheme)
+      await page.addInitScript((theme) => localStorage.setItem('rp-theme', theme), scheme)
       await new InboxPage(page).goto()
       expect(await page.evaluate(() => document.documentElement.dataset.theme)).toBe(scheme)
       await expectNoNewA11yViolations(page, `inbox${suffix}`)