feat: Phase 1 — Authentik auth, MCP endpoint, persistent memory

End-to-end Phase 1 of shared-memory: a logged-in Authentik user can sign
into the Web UI (/me debug page), and an MCP client with an Authentik-
issued bearer token can call memory.write / memory.list / memory.get /
memory.delete plus project.identify against /api/mcp.

Stack:
- Next.js 15 (App Router) + React 19 + TypeScript, pnpm workspaces
- Drizzle ORM + Postgres 16 + pgvector + pg_trgm
- Auth.js v5 with Authentik provider (Web UI)
- jose + Authentik JWKS for MCP bearer-token validation
- JSON-RPC 2.0 dispatcher implementing the MCP wire protocol over plain
  HTTP POST (hand-rolled to fit Next.js App Router; switches to SSE in a
  later phase if server-initiated events are needed)
- bge-small embeddings sidecar deferred to Phase 2; the schema already
  reserves the vector(384) column + IVFFlat index, FTS via a STORED
  tsvector column, and the visibility enum (private/shared/team) so
  cross-user memory sharing can be added without a future migration

Deployment supports two modes (set in .env, never committed):
- Behind an external reverse proxy (HAProxy / nginx / Cloudflare Tunnel /
  Traefik) — DEFAULT; the app exposes APP_PORT on the host with
  X-Forwarded-* trusted, no in-container TLS
- Built-in TLS via Caddy — opt-in with `docker compose --profile tls up`

Discovery endpoint at /.well-known/oauth-protected-resource (RFC 9728)
points MCP clients at the Authentik authorization server after a 401.

README walks through both Authentik providers (Web UI + MCP resource
server), the audience scope mapping, redirect URIs, and includes a worked
HAProxy config snippet.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Caddyfile

@@ -0,0 +1,33 @@
+# Caddy config for shared-memory.
+#
+# Hostname and ACME email come from environment variables set by docker-compose
+# (which loads them from .env). For local development without TLS, override
+# this file or set APP_HOSTNAME=localhost and use a docker-compose override.
+
+{
+	email {$ACME_EMAIL}
+	# Uncomment to use the Let's Encrypt staging directory while testing:
+	# acme_ca https://acme-staging-v02.api.letsencrypt.org/directory
+}
+
+{$APP_HOSTNAME} {
+	encode gzip zstd
+
+	# Trust X-Forwarded-* from this proxy. Auth.js + Next.js use these to
+	# construct callback URLs that match PUBLIC_URL.
+	header {
+		# Tell upstream we terminated TLS.
+		# (`reverse_proxy` already sets X-Forwarded-* by default.)
+	}
+
+	reverse_proxy app:3000 {
+		header_up Host {host}
+		header_up X-Real-IP {remote_host}
+		header_up X-Forwarded-Proto {scheme}
+	}
+
+	log {
+		output stdout
+		format console
+	}
+}