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/delivery-schema.md

@@ -1,7 +1,7 @@
 # Delivery and Keys Schema
 
-**Proto files:** `proto/qpq/v1/delivery.proto`, `proto/qpq/v1/keys.proto`
-**Package:** `qpq.v1`
+**Proto files:** `proto/qpc/v1/delivery.proto`, `proto/qpc/v1/keys.proto`
+**Package:** `qpc.v1`
 **Method IDs:** 200-205 (delivery), 300-304 (key packages and hybrid keys), 510-520 (key transparency)
 
 This page documents the Protobuf message definitions for the delivery service (store-and-forward message relay) and the key management service (MLS KeyPackages, hybrid post-quantum keys, and key transparency).
@@ -16,7 +16,7 @@ The delivery service is a store-and-forward relay. It is intentionally MLS-unawa
 
 ```protobuf
 syntax = "proto3";
-package qpq.v1;
+package qpc.v1;
 
 // Delivery service: enqueue, fetch, peek, ack, batch (6 methods).
 // Method IDs: 200-205.
@@ -221,7 +221,7 @@ Key management for MLS KeyPackages, hybrid post-quantum keys, and key transparen
 
 ```protobuf
 syntax = "proto3";
-package qpq.v1;
+package qpc.v1;
 
 // Key package + hybrid key CRUD (5 methods).
 // Method IDs: 300-304.