docs: add deployment & operations guide and expand docs, README and configuration reference

[CJackHwang]

Motivation

• Provide a practical deployment and long‑running operations guide to help users run the service in production scenarios.
• Make configuration defaults and important runtime knobs clearer in the top‑level README and the configuration reference.
• Improve API, quick‑start and troubleshooting documentation to reduce onboarding and operational friction.

Description

• Add a new docs/deployment-and-operations.md with guidance for direct and Docker deployments, systemd examples, maintenance commands, and upgrade recommendations.
• Update README.md to clarify configuration default behavior, add a link to the new deployment guide, and clarify the client API key instruction.
• Rework docs/README.md to reflect the new guide and reorganize the document index.
• Expand docs/api-usage.md with structured sections for health, chat completions, API key auth, queue management, and server management endpoints.
• Enrich docs/configuration-reference.md with detailed tables of configuration options and defaults, plus Function Calling and Cookie Refresh sections.
• Improve docs/quick-start.md, docs/troubleshooting.md, docs/auth-rotation-cookie-refresh.md, and docs/development-and-release.md with clearer step sequences, checks, and recommended commands.
• Small copy/clarity edits across doc files and added references to launch_camoufox.py, Docker usage, and important endpoints.

Testing

• Ran code quality and type checks via poetry run ruff check . and poetry run pyright, which passed.
• Executed unit/integration tests using poetry run pytest, which completed successfully.
• Verified quick‑start and health check commands in examples such as curl http://127.0.0.1:2048/health for documentation accuracy.

---

Codex Task

[chatgpt-codex-connector]

Codex usage limits have been reached for code reviews. Please check with the admins of this repo to increase the limits by adding credits.
Credits must be used to enable repository wide code reviews.