fix examples: http-server and websocket

[cs01]

fix examples: http-server and websocket

Summary

• http-server: replace raw JSON strings with c.json() object literals; serve an embedded HTML homepage with clickable routes and inline POST forms
• websocket: fix crash on open (removed wsBroadcast call on connect), iMessage-style chat UI (white/blue bubbles, sender names, arrow button), client-generated IDs, structured sender|text message protocol, fixed status var shadowing window.status, constrained container width on wide screens
• http redirect fixes: set hasHeaders=true when handler returns HttpResponse from .d.ts; use embedDir not embedFile for getEmbeddedFile lookup

Changes

examples/http-server.ts

• All c.json() calls now pass object literals instead of raw JSON strings
• Root route serves embedded index.html (HTML homepage with all routes)
• New examples/http-server-public/index.html with clickable GET links and inline POST forms

examples/websocket/

• app.ts: remove wsBroadcast on open (caused crash), structured sender|text protocol, removed redundant interface definitions (use .d.ts)
• public/chat.js: client-generated UUID, parse structured messages, distinguish sent/received sides
• public/style.css: iMessage-style bubbles, full-screen layout, constrained width

src/codegen/llvm-generator.ts

• Support embedDir for embedded file lookup (fixes blank page on redirect)

Test plan

• node dist/chad-node.js run examples/http-server.ts — homepage loads, all routes return JSON
• node dist/chad-node.js run examples/websocket/app.ts — chat UI loads, messages appear with correct sender/receiver styling, user count updates on leave
• Multiple browser tabs — broadcast works, leave message shown to remaining users
• bash scripts/run-examples.sh — all 9 example tests pass