chore: rename quicproquo → quicprochat in docs, Docker, CI, and packaging

Rename all project references from quicproquo/qpq to quicprochat/qpc
across documentation, Docker configuration, CI workflows, packaging
scripts, operational configs, and build tooling.

- Docker: crate paths, binary names, user/group, data dirs, env vars
- CI: workflow crate references, binary names, artifact names
- Docs: all markdown files under docs/, SDK READMEs, book.toml
- Packaging: OpenWrt Makefile, init script, UCI config (file renames)
- Scripts: justfile, dev-shell, screenshot, cross-compile, ai_team
- Operations: Prometheus config, alert rules, Grafana dashboard
- Config: .env.example (QPQ_* → QPC_*), CODEOWNERS paths
- Top-level: README, CONTRIBUTING, ROADMAP, CLAUDE.md

sdks/web/public/index.html

@@ -4,7 +4,7 @@
   <meta charset="utf-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1" />
   <meta name="theme-color" content="#58a6ff" />
-  <title>quicproquo</title>
+  <title>quicprochat</title>
   <link rel="manifest" href="manifest.json" />
   <link rel="stylesheet" href="style.css" />
 </head>
@@ -12,7 +12,7 @@
   <div id="app">
     <!-- Login screen -->
     <div id="login-screen" class="screen">
-      <h1>quicproquo</h1>
+      <h1>quicprochat</h1>
       <p class="subtitle">End-to-end encrypted messenger</p>
       <form id="login-form">
         <input id="server-input" type="text" placeholder="Server (ws://host:port)" value="ws://127.0.0.1:9000" />