Add QR pairing (terminal QR, in-app scanner, iris://pair deep link)

docs/19-http-fallback-transport.md

@@ -71,7 +71,7 @@ acceptable alternative if preferred).
 
 ```
                         ┌──────────────────────── hermes gateway process ───────────────────────┐
-                        │  AndroidAdapter                                                       │
+                        │  IrisAdapter                                                       │
                         │    │  frames (same protocol.Frame objects)                            │
                         │    ▼                                                                  │
                         │  _broadcast_or_log ──► outbox.append(cursor) ──► push (if no live)    │
@@ -105,7 +105,7 @@ over HTTP whenever the WS is down.
 
 ## 19.4 Gateway: `gateway-plugin/http_server.py`
 
-New module, started/stopped by `AndroidAdapter.connect()`/`disconnect()` next
+New module, started/stopped by `IrisAdapter.connect()`/`disconnect()` next
 to the WS server.
 
 - **Server:** `http.server.ThreadingHTTPServer` + `BaseHTTPRequestHandler`,
@@ -114,8 +114,8 @@ to the WS server.
   into the gateway's asyncio loop with
   `asyncio.run_coroutine_threadsafe(coro, loop)` (the loop is captured at
   start, same loop the WS server runs on).
-- **Config:** `ANDROID_HTTP_PORT` (default **8791**), same bind host as the WS
-  (`ANDROID_WS_HOST`). Optional TLS via `ANDROID_HTTP_CERT`/`ANDROID_HTTP_KEY`
+- **Config:** `IRIS_HTTP_PORT` (default **8791**), same bind host as the WS
+  (`IRIS_WS_HOST`). Optional TLS via `IRIS_HTTP_CERT`/`IRIS_HTTP_KEY`
   (`ssl.SSLContext` on the server) — same posture as the WS: plaintext on a
   trusted LAN by default, TLS for remote/Tailscale setups.
 - **Bind failure is NON-fatal** (unlike the WS): log a warning, disable the
@@ -151,7 +151,7 @@ Wire format (standard SSE, three fields):
 ```
 id: 1043
 event: frame
-data: {"v":1,"type":"message","chat_id":"android:default",...}
+data: {"v":1,"type":"message","chat_id":"default",...}
 
 : hb                      ← comment heartbeat every 15 s (keeps proxies alive)
 ```