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

docs/src/wire-format/auth-schema.md

@@ -1,7 +1,7 @@
 # Auth Schema
 
-**Proto file:** `proto/qpq/v1/auth.proto`
-**Package:** `qpq.v1`
+**Proto file:** `proto/qpc/v1/auth.proto`
+**Package:** `qpc.v1`
 **Method IDs:** 100-103
 
 The auth proto defines the OPAQUE asymmetric password-authenticated key exchange (PAKE) messages used for user registration and login. OPAQUE never transmits the password to the server; the server learns only a random value derived from the password.
@@ -16,7 +16,7 @@ See [Authentication Service Internals](../internals/authentication-service.md) f
 
 ```protobuf
 syntax = "proto3";
-package qpq.v1;
+package qpc.v1;
 
 // OPAQUE registration + login (4 methods).
 // Method IDs: 100-103.