Add GET /api/cli-profiles/templates returning copy-ready config snippets
for pointing common AI clients at this gateway: Cursor, VS Code Continue,
Claude Code, and a generic OpenAI-compatible blob.
Ported from AQBot's list_gateway_templates (a desktop app that hardcodes
localhost:8080). Adapted for server-side use: the gateway origin is resolved
per request — ?base_url= override, then X-Forwarded-Proto + Host (correct
behind a TLS-terminating proxy), then config server.host:port fallback
(0.0.0.0/:: rewritten to 127.0.0.1, matching the comfyui-agent local-base
convention). OpenAI-compatible clients get the /v1 base; Claude Code gets
the bare origin since it appends /v1/messages itself.
Scope guard: this only returns config strings + copy hints. It deliberately
does not rewrite local CLI config files (AQBot's desktop cli_config behavior),
which has no meaning on a server.
New module proxy::cli_profiles::templates holds the snippet content; the admin
handler resolves the origin. Covered by 9 unit tests.