fix(ingestion): authenticate the REST API; confine ingest paths to brain/raw/ (#149) (#152)

Co-authored-by: Mathias <mthbqv@gmail.com>

AGENTS.md

@@ -299,7 +299,7 @@ entries that age well are about *why*, *how to avoid*, and *what to do when*.
 |---------|-------|-------|
 | **Claude Code, Claude Desktop** | `brain_query` (BM25), `brain_answer` (LLM-synth + sources) MCP tools | `brain_write` MCP tool |
 | **Crush, Pi, Antigravity, other MCP-capable** | same MCP server: `ingestion-brain` (via the `mcp__*_brain__*` namespace once authenticated) | same |
-| **Anything HTTP-only (curl, scripts)** | `POST https://brain-mcp.d-ma.be/query` with `{"query":"..."}` (auth via `BRAIN_MCP_TOKEN`) | `POST .../write` with `{"content":"...","filename":"..."}` |
+| **Anything HTTP-only (curl, scripts)** | Tailnet only: `POST https://koala.tail30472e.ts.net:8443/query` with `{"query":"..."}`, sending `BRAIN_MCP_TOKEN` (not yet enforced on REST, hyperguild#149). The public `brain-mcp.d-ma.be` serves `/mcp` only (infra#517). | `POST .../write` with `{"content":"...","wing":"...","hall":"..."}` |
 | **Browser / human inspection** | `https://git.d-ma.be/mathias/hyperguild` → `knowledge/` and `wiki/` markdown files |
 
 - **Scoping — the brain holds no confidential client content.** Nothing on the read path
@@ -488,7 +488,11 @@ the routing pod; brain tools moved to the brain MCP.
 
 The brain HTTP REST API (`/query`, `/write`, `/ingest`, `/ingest-raw`,
 `/ingest-path`, `/backfill-refs`, `/pass-rate`) remains available on port 3300
-for shell scripts and non-MCP clients.
+for shell scripts and non-MCP clients, **with the same bearer token as `/mcp`**
+(`BRAIN_MCP_TOKEN`; hyperguild#149). It is not served on the public host
+(infra#517): use the tailnet (`koala:8443`) or in-cluster
+`ingestion.supervisor.svc:3300`. `/ingest-path` and `brain_ingest` `path`
+accept only paths inside `brain/raw/`.
 
 `brain_answer(query)` performs BM25 retrieval + LLM synthesis (berget.ai
 gemma4:31b → iguana fallback). `brain_classify(text)` infers doc type, title,