feat: WIP element Chat intergration

apps/edr-freight-api/.env.example

@@ -219,3 +219,22 @@ EIMS_AUTO_SUBMIT=false
 EIMS_AUTO_SUBMIT_CRON=0 */5 * * * *
 # MoR rejects documents older than 3 days; the sweep will not attempt those.
 EIMS_AUTO_SUBMIT_MAX_AGE_DAYS=3
+# ── Internal chat (Matrix/Element) ──────────────────────────────────────────
+# Disabled by default; /chat/sso and the nightly room/membership reconcile are
+# no-ops until enabled. See infrastructure/matrix/.
+MATRIX_ENABLED=false
+# Synapse URL reachable from this container (docker-compose service DNS in
+# prod, e.g. http://synapse:8008 — NOT the public https://matrix.edr.et).
+MATRIX_BASE_URL=http://localhost:8008
+# Synapse's own public_baseurl — what Element itself is configured to call.
+# Only used to seed the sso.html handoff page's localStorage.
+MATRIX_PUBLIC_BASE_URL=https://matrix.edr.et
+MATRIX_CHAT_WEB_URL=https://chat.edr.et
+MATRIX_SERVER_NAME=matrix.edr.et
+# Must exactly match infrastructure/matrix/synapse/.env's MATRIX_JWT_SECRET —
+# this is the whole trust boundary for the SSO handoff.
+MATRIX_JWT_SECRET=
+# access_token of a Synapse server-admin account. Bootstrap it once via
+# infrastructure/matrix/synapse's MATRIX_REGISTRATION_SHARED_SECRET (see that
+# file's comments) — this app never touches the shared secret itself.
+MATRIX_ADMIN_TOKEN=