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

justfile

@@ -1,4 +1,4 @@
-# quicproquo v2 — build commands
+# quicprochat v2 — build commands
 
 # Default: build all workspace crates
 build:
@@ -10,27 +10,27 @@ test:
 
 # Run core crypto tests only
 test-core:
-    cargo test -p quicproquo-core
+    cargo test -p quicprochat-core
 
 # Build proto crate (triggers prost codegen)
 proto:
-    cargo build -p quicproquo-proto
+    cargo build -p quicprochat-proto
 
 # Build RPC framework
 rpc:
-    cargo build -p quicproquo-rpc
+    cargo build -p quicprochat-rpc
 
 # Build SDK
 sdk:
-    cargo build -p quicproquo-sdk
+    cargo build -p quicprochat-sdk
 
 # Build server
 server:
-    cargo build -p quicproquo-server
+    cargo build -p quicprochat-server
 
 # Build client
 client:
-    cargo build -p quicproquo-client
+    cargo build -p quicprochat-client
 
 # Check all with clippy
 lint: