Re-add MCP bridge so Hermes can delegate to the real Claude Code CLI

Recreates the PR #17 change (closed without merging, then asked for back
after confirming a real ANTHROPIC_API_KEY would mean separate/duplicate
billing rather than actually using the Pro/Max subscription).

New POST /mcp endpoint (Streamable HTTP transport, stateless — fresh
McpServer+transport per request) exposing one tool, ask_claude_code: runs
the real `claude` binary against a prompt, billed against the subscription
rather than API credits. Works specifically because it's the actual CLI
making the request server-side. Read-only — no Edit/Write/git-push/
git-commit tools.

Also removes litellm-config.yaml's "anthropic-claude" model entry: it only
ever worked when the real claude CLI itself was the caller (proven earlier),
so having it listed as a selectable model was actively misleading — Hermes
picking it directly is exactly what produced the '401: Missing Anthropic
API Key' confusion that led back to this bridge. The MCP tool is the actual
working path now; general_settings.forward_client_headers_to_llm_api is
also removed since nothing uses it anymore.

Tested end-to-end locally again before pushing (built the image, ran it,
full MCP handshake via curl) — real 'pong' from the real claude CLI.

litellm-config.yaml

@@ -11,18 +11,15 @@ model_list:
       model: openrouter/openai/gpt-4o-mini
       api_key: os.environ/OPENROUTER_API_KEY
 
-  # Routes to Anthropic using the CALLER's forwarded Authorization header (the Claude
-  # Pro/Max subscription OAuth token) instead of a LiteLLM-held API key — billed against
-  # the subscription, not per-token. CONFIRMED WORKING, but only for the real `claude`
-  # CLI binary as caller (tested: `claude -p` with ANTHROPIC_BASE_URL pointed here
-  # returned a real completion). An earlier test with plain curl replicating the same
-  # request shape failed — Anthropic apparently requires header/fingerprint details only
-  # the real CLI sends, which LiteLLM faithfully relays but a hand-built request won't
-  # have. Do NOT expect this to work for other callers (Hermes, generic HTTP clients) —
-  # they aren't the real CLI and can't reproduce that fingerprint.
-  - model_name: anthropic-claude
-    litellm_params:
-      model: anthropic/claude-sonnet-5
+  # NOT included: an "anthropic-claude" model routing to Anthropic via the caller's
+  # forwarded OAuth header (general_settings.forward_client_headers_to_llm_api). It
+  # genuinely works — but ONLY when the real `claude` CLI binary is the caller (its
+  # request carries a header/fingerprint only that binary sends; a hand-built request,
+  # including Hermes selecting this model directly, gets a hard auth error from
+  # Anthropic). Having it selectable here caused exactly that confusion once already.
+  # The actual working path for "Hermes uses the Claude subscription" is the MCP bridge
+  # at claude-agent's /mcp (agent/src/mcpBridge.js) — it shells out to the real `claude`
+  # binary server-side instead of trying to make an arbitrary caller impersonate it.
 
 litellm_settings:
   # Callers (Hermes included) send provider-specific params like reasoning_effort that
@@ -30,5 +27,4 @@ litellm_settings:
   drop_params: true
 
 general_settings:
-  forward_client_headers_to_llm_api: true
   master_key: os.environ/LITELLM_MASTER_KEY