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

.env.example

@@ -1,20 +1,20 @@
-# quicproquo Production Environment Variables
+# quicprochat Production Environment Variables
 # Copy this file to .env and fill in the values.
 
 # Server auth token (required, >= 16 characters)
-QPQ_AUTH_TOKEN=
+QPC_AUTH_TOKEN=
 
 # SQLCipher database encryption key (required for store_backend=sql)
-QPQ_DB_KEY=
+QPC_DB_KEY=
 
 # Ports (defaults shown)
-QPQ_LISTEN_PORT=7000
-QPQ_WS_PORT=9000
+QPC_LISTEN_PORT=7000
+QPC_WS_PORT=9000
 
 # Optional features
-QPQ_SEALED_SENDER=false
-QPQ_REDACT_LOGS=true
-QPQ_WS_LISTEN=
+QPC_SEALED_SENDER=false
+QPC_REDACT_LOGS=true
+QPC_WS_LISTEN=
 
 # Grafana admin password (required — must be strong, no default)
 GRAFANA_ADMIN_PASSWORD=