docs+plugin: HTTP-only transport cleanup, install guide, review fixes

- docs/install.md: new end-to-end guide for non-technical users
  (gateway install, app install, LAN/TLS/remote connection, push,
  options, troubleshooting); docs/setup.md now points to it
- README: new 'Install the gateway' section; pairing section updated
  for HTTP transport (8791, QR scan on Android)
- rename IRIS_WS_HOST -> IRIS_HTTP_HOST (clean rename, no compat
  fallback); drop dead DEFAULT_PORT=8790
- setup.py: advertise https:// in the printed/QR server URL when
  IRIS_HTTP_CERT is set
- ws_probe.py/e2e.py: default --url http://127.0.0.1:8791, env
  IRIS_WS_URL -> IRIS_HTTP_URL, honor explicit port + https scheme
- plugin.yaml: IRIS_HTTP_* env names, description no longer says
  'WebSocket server'
- docs 03/09/12/19: fix stale WS-era refs (ws_server.py cites,
  8790 smoke test, WSS->HTTPS, 'HTTP fallback' reframed as the
  only transport)
- AGENTS.md: symlink name android -> iris (matches actual install)
- test: adapter reads IRIS_HTTP_HOST/CERT/KEY from env; legacy
  IRIS_WS_* names are not consulted (95/95 pass)

docs/03-gateway-plugin.md

@@ -27,13 +27,13 @@ requires_env:
     prompt: "Iris pairing token"
     password: true
 optional_env:
-  - name: IRIS_WS_HOST
-    description: "WS bind host (default 127.0.0.1; use 0.0.0.0 for LAN)"
-    prompt: "WS host"
+  - name: IRIS_HTTP_HOST
+    description: "HTTP bind host (default 127.0.0.1; use 0.0.0.0 for LAN)"
+    prompt: "HTTP host"
     password: false
-  - name: IRIS_WS_PORT
-    description: "WS port (default 8790)"
-    prompt: "WS port"
+  - name: IRIS_HTTP_PORT
+    description: "HTTP port (default 8791)"
+    prompt: "HTTP port"
     password: false
   - name: IRIS_HOME_CHANNEL
     description: "Default chat id for cron/notification delivery (default default)"
@@ -67,13 +67,13 @@ optional_env:
     description: "ntfy server URL (default https://ntfy.sh)"
     prompt: "ntfy server URL"
     password: false
-  - name: IRIS_WS_CERT
-    description: "TLS cert path for WSS (optional)"
-    prompt: "WSS cert"
+  - name: IRIS_HTTP_CERT
+    description: "TLS cert path for HTTPS (optional)"
+    prompt: "HTTPS cert"
     password: false
-  - name: IRIS_WS_KEY
-    description: "TLS key path for WSS (optional)"
-    prompt: "WSS key"
+  - name: IRIS_HTTP_KEY
+    description: "TLS key path for HTTPS (optional)"
+    prompt: "HTTPS key"
     password: false
 ```
 
@@ -215,27 +215,26 @@ The adapter tracks per-chat **turn state** (in-turn, current streaming
 `message` vs `tool.*` vs `commentary`. The exact classification markers are
 verified empirically in M2 (see `13-testing.md`).
 
-## 3.4 WebSocket server (`ws_server.py`)
+## 3.4 HTTP server (`http_server.py`)
 
-- Library: **`websockets`** (core dep, v15). `websockets.serve(handler, host,
-  port, ssl=ctx)`.
-- **Handler** per connection:
-  1. Await first frame; must be `hello {token, device_id, device_name, caps,
-     fcm_token?}`. Verify token (constant-time) + allowlist. On failure: send
-     `error {code:"auth"}` and close.
-  2. On success: register in connection registry
-     (`device_id → {ws, caps, fcm_token}`), send
-     `hello.ack {server_caps, sync_cursor, channels[]}`.
-  3. Loop: decode frames, dispatch to adapter inbound handlers.
-  4. On close: deregister; if no devices remain, ensure pending outbox
-     frames have push fired.
+- Library: **stdlib `http.server`** (`ThreadingHTTPServer` +
+  `BaseHTTPRequestHandler`) in a daemon thread; bridges into the gateway's
+  asyncio loop via `asyncio.run_coroutine_threadsafe`. Optional TLS via
+  `ssl.SSLContext` (`IRIS_HTTP_CERT`/`IRIS_HTTP_KEY`). Full design:
+  `19-http-fallback-transport.md`.
+- **Auth:** `Authorization: Bearer <token>` (constant-time `verify_token`)
+  - device allowlist via `X-Iris-Device`; `401` on failure.
+- **Endpoints:** `GET /v1/health` (unauthenticated liveness),
+  `POST /v1/frame` (any JSON frame the protocol accepts),
+  `GET /v1/events?cursor=N` (SSE: outbox catch-up + live frames),
+  `GET /v1/poll?cursor=N` (long-poll fallback), `POST /v1/media` +
+  `GET /v1/media/{id}` (media upload/pull).
 - **Routing:** `emit(chat_id, frame)` → broadcast to **all** connected
   devices (no per-chat subscribe; single-user model). Global frames
   (`channel.*`, `status`) also broadcast to all.
-- **Heartbeat:** WS ping/pong + app-level `ping`/`pong`; dead peers reaped.
-- **Backpressure:** per-connection send queue with a bounded buffer; drop
-  `message.update` (coalesce to latest) under pressure, never drop
-  `message`/`tool.end`/`notification`.
+- **Limits:** 64 KiB request body cap, per-device token-bucket rate limit
+  (20/s, burst 40) → `429`; media uploads bounded by the per-upload total
+  cap. No CORS (app clients only).
 
 ## 3.5 State & storage (all under `get_hermes_home()/"iris"`)
 
@@ -253,18 +252,19 @@ verified empirically in M2 (see `13-testing.md`).
 ## 3.6 Config resolution
 
 - **Secrets (`.env`):** `IRIS_TOKEN`, `IRIS_FCM_SERVICE_ACCOUNT`,
-  `IRIS_FCM_SERVER_KEY`, `IRIS_WS_CERT/KEY`, `NTFY_TOPIC` (if secret).
+  `IRIS_FCM_SERVER_KEY`, `IRIS_HTTP_CERT/KEY`, `NTFY_TOPIC` (if secret).
 - **Behavioral (`config.yaml` → `gateway.platforms.iris.extra`):** `host`,
-  `port`, `home_channel`, `allowed_users`, `push_backend`, `outbox_retention_hours`,
-  `max_upload_bytes`, `tls`.
+  `http_port`, `home_channel`, `allowed_users`, `push_backend`, `outbox_retention_hours`,
+  `max_upload_bytes`, `http_cert`/`http_key`.
 - Env vars override `config.yaml` (hermes convention). Read secrets with the
   scope-aware `_get_scoped_secret` pattern (see `plugins/platforms/irc/adapter.py:42`)
   so multiplexed profiles don't leak each other's tokens.
 
 ## 3.7 Failure & lifecycle safety
 
-- WS server bind failure → `_set_fatal_error("bind_failed", …, retryable=True)`.
-- All outbound sends are best-effort; a dead socket latches and the frame falls
-  to the outbox.
-- `disconnect()` cancels the server task and closes sockets cleanly.
+- HTTP server bind failure → non-fatal: log a warning, disable the HTTP leg,
+  show it in the inspector (the plugin keeps working for other platforms).
+- All outbound sends are best-effort; a dead stream latches and the frame
+  falls to the outbox.
+- `disconnect()` stops the HTTP server and closes streams cleanly.
 - Token/PII redaction in all logs (hermes PII policy).