doc(packages): add the host/ and client/ group READMEs and table rows

Both web-GUI groups shipped without the group README that the packages
table names as each group's canonical package/ctx-key map, and without
rows in that table. Adds both bilingual pairs, the two table rows
(ceiling 835→870: two genuinely new product groups joined the canonical
table at minimal row width), and fixes webserver README drift
(WebServerService/ctx.webServer → HttpServerService/ctx.httpServer,
matching src/index.ts).

scripts/doc-budgets.manifest.json

@@ -7,5 +7,5 @@
   "docs/testing.md": 1100,
   "examples/AGENTS.md": 310,
   "packages/AGENTS.md": 675,
-  "packages/README.md": 835
+  "packages/README.md": 870
 }