docs: restructure around source-of-truth pages

- CONTEXT.md glossary
- README reduced to intro, quickstart and doc index
- new architecture.md, gateway.md (from proxy-key-onboarding.md),
  operations.md; network-access.md rewritten
- coding-cli-setup: stale OMNIROUTE_PORT:-4000 endpoint, terms and
  duplicated per-slot/classifier explanations fixed
- research/README.md index; proxy-request-priority.md moved there as
  superseded

Every doc names keys instead of restating values and links its source.

Refs #55 (#56, #57, #59, #60)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CONTEXT.md

@@ -0,0 +1,59 @@
+# LLM-Server
+
+A self-hosted inference stack: local models served on one GPU machine, reached by other tools through a single authenticated entry point. This file is a glossary only — for how things are configured, follow the links in the docs to the source.
+
+## Language
+
+### Machine
+
+**Server**:
+The one machine that runs the stack.
+_Avoid_: AI box, R9700 box, this machine
+
+**Host**:
+The Docker host, as opposed to a container — only used for that distinction.
+_Avoid_: using it as a synonym for Server
+
+### Serving models
+
+**Backend**:
+A model server process that serves one model to the gateway (`llama-server`, `qwen-classifier`).
+_Avoid_: provider, model server
+
+**Slot**:
+One concurrent request lane inside a backend; a backend handles as many requests at once as it has slots.
+_Avoid_: parallel request, lane
+
+**Main model**:
+The large model that does the actual work for workloads.
+_Avoid_: chat model
+
+**Classifier model**:
+The small model that judges a coding CLI's tool calls before they run.
+_Avoid_: fast model (`fastModel` only when quoting qwen-code's config key)
+
+### Reaching the models
+
+**Gateway**:
+The single entry point every model call goes through (OmniRoute).
+_Avoid_: proxy, AI proxy
+
+**Provider connection**:
+The gateway's registration of one backend.
+_Avoid_: provider (alone), connection (alone)
+
+**API key**:
+A credential issued by the gateway to exactly one workload.
+_Avoid_: virtual key, workload key
+
+**Workload**:
+Anything that calls the gateway with its own API key.
+_Avoid_: client, consumer
+
+**Coding CLI**:
+A workload that is an interactive coding agent (Claude Code, Kimi CLI, OpenCode, Qwen Code).
+_Avoid_: harness
+
+**Reverse proxy**:
+The existing Nginx Proxy Manager instance that publishes the gateway under hostnames; not part of this stack.
+_Avoid_: proxy (alone)