docs(coding-cli-setup): split per-CLI docs into their own files

Move docs/coding-cli-setup.md to docs/coding-cli-setup/ with one file
per CLI (claude-code, kimi-cli, opencode, qwen-code) plus a shared
index.md for the gateway intro, tool-calling risk note, and summary
table.

Also fixes the qwen-code doc: context sizes are per-slot
(LLAMA_CTX_SIZE / LLAMA_PARALLEL), not raw LLAMA_CTX_SIZE (same fix
applied to OpenCode's limit.context); documents the fastModel
classifier provider and its own context math; adds the omniroute-search
MCP server (SearXNG web search) and Auto Mode permissions tuning that
were missing from the original qwen-code section.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/coding-cli-setup/claude-code.md

@@ -0,0 +1,13 @@
+# Claude Code CLI
+
+[← back to overview](index.md)
+
+Claude Code speaks the **Anthropic Messages API** — point it at the gateway's unified endpoint, not llama.cpp directly:
+
+```bash
+export ANTHROPIC_BASE_URL=http://<ai-box>:${OMNIROUTE_PORT:-4000}
+export ANTHROPIC_API_KEY=<claude-code-cli virtual key>
+claude
+```
+
+Requires llama.cpp's `--jinja` flag (already set in `docker-compose.yml`) — without it, tool-use requests fail outright.