Merge pysim-otaman-server into otaman (monorepo, v1.7.0)

- Move PWA into frontend/; server package at pysim_otaman_server/
- Server now serves the PWA (same origin -> no CORS/PNA): static file handler
  + --web-dir flag + injects window.PYSIM_EMBEDDED marker into index.html
- Frontend defaults to relative API base when embedded (pysimBase = '')
- Version 1.7.0 aligned: server.py VERSION, pyproject.toml, PWA header
- SW cache bump otaman-v7 -> otaman-v8
- Docs: combined README + docs/api.md endpoint reference; update links
- Fix stale package.json repository URL

frontend/tailwind.config.js

@@ -0,0 +1,13 @@
+/** @type {import('tailwindcss').Config} */
+module.exports = {
+  darkMode: 'class',
+  content: ['./index.html', './help.html', './help-ru.html'],
+  theme: {
+    extend: {
+      textColor: {
+        heading: '#1e293b',
+      },
+    },
+  },
+  plugins: [],
+}