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

docs/04-wire-protocol.md

@@ -12,7 +12,7 @@ Every frame:
   "v": 1,
   "id": 42,                 // optional; present on requests + their responses
   "type": "message",        // frame type (below)
-  "chat_id": "android:default",   // optional; scope for chat-scoped frames
+  "chat_id": "default",   // optional; scope for chat-scoped frames
   "thread_id": "t_123",           // optional
   "payload": { }             // type-specific object
 }
@@ -43,7 +43,7 @@ Pairing succeeded.
                  "search":true,"push":"fcm","pickers":true},
   "sync_cursor":1042,
   "last_pushed_cursor":1040,
-  "channels":[{"chat_id":"android:default","name":"Default","kind":"default","is_default":true}]
+  "channels":[{"chat_id":"default","name":"Default","kind":"default","is_default":true}]
 }}
 ```
 
@@ -57,7 +57,7 @@ woke the device via push (dedupe, `08-push.md` §8.7).
 A final / standalone message.
 
 ```json
-{"type":"message","chat_id":"android:default","thread_id":null,
+{"type":"message","chat_id":"default","thread_id":null,
  "payload":{
    "message_id":"m_9001","role":"assistant",
    "text":"Here is the answer…",
@@ -107,7 +107,7 @@ them drop the message(s) from their cache. Also outboxed, so a device that was
 offline learns of the deletion on its next `sync`.
 
 ```json
-{"type":"message.deleted","id":30,"chat_id":"android:default","thread_id":null,
+{"type":"message.deleted","id":30,"chat_id":"default","thread_id":null,
  "payload":{"message_ids":["m_9001","m_9002"]}}
 ```
 
@@ -176,7 +176,7 @@ Channel directory updates. **Broadcast to all connected devices** (no explicit
 subscribe; the server pushes to every open WS).
 
 ```json
-{"type":"channel.created","payload":{"chat_id":"android:chan_7","name":"Cron Reports",
+{"type":"channel.created","payload":{"chat_id":"chan_7","name":"Cron Reports",
    "kind":"channel","parent_chat_id":null}}
 ```
 
@@ -190,7 +190,7 @@ title.
 Response to a `history` request. Returns a page of messages for a chat/thread.
 
 ```json
-{"type":"history","id":20,"chat_id":"android:default","thread_id":null,
+{"type":"history","id":20,"chat_id":"default","thread_id":null,
  "payload":{
    "messages":[
      {"message_id":"m_8990","role":"user","text":"Hi","ts":1723990000000},
@@ -244,9 +244,9 @@ Response to a `commands.complete` request. Autocomplete matches for a typed pref
 Agent lifecycle for a chat/thread. App shows a "thinking…" indicator on `busy`.
 
 ```json
-{"type":"agent.busy","chat_id":"android:default","thread_id":null,
+{"type":"agent.busy","chat_id":"default","thread_id":null,
  "payload":{"reason":"processing"}}
-{"type":"agent.idle","chat_id":"android:default","thread_id":null,"payload":{}}
+{"type":"agent.idle","chat_id":"default","thread_id":null,"payload":{}}
 ```
 
 `reason` ∈ `processing | tool | waiting_input | cron`.
@@ -256,7 +256,7 @@ Agent lifecycle for a chat/thread. App shows a "thinking…" indicator on `busy`
 ```json
 {"type":"search.results","id":7,"payload":{
    "query":"deploy","scope":"all","hits":[
-     {"message_id":"m_123","chat_id":"android:chan_7","thread_id":null,
+     {"message_id":"m_123","chat_id":"chan_7","thread_id":null,
       "role":"assistant","snippet":"…deploy the service…","ts":1723900000000}]}}
 ```
 
@@ -275,7 +275,7 @@ The gateway acknowledges that the agent has received and started processing
 the user's message. The app uses it to show ✓✓ on user bubbles.
 
 ```json
-{"type":"read.receipt","chat_id":"android:default","payload":{"message_id":"m_9001"}}
+{"type":"read.receipt","chat_id":"default","payload":{"message_id":"m_9001"}}
 ```
 
 Emitted to the originating connection when a `message.send` is accepted for
@@ -319,7 +319,7 @@ First frame; auth + caps.
 
 ```json
 {"type":"hello","payload":{
-   "token":"<ANDROID_TOKEN>","device_id":"dev_a1b2","device_name":"MIX 2S",
+   "token":"<IRIS_TOKEN>","device_id":"dev_a1b2","device_name":"MIX 2S",
    "caps":{"min_protocol":1,"media":true,"push":"fcm"},
    "fcm_token":"<FCM token>","ntfy_topic":"<topic, if ntfy>"}}
 ```
@@ -329,7 +329,7 @@ First frame; auth + caps.
 Send text (or a `/slash-command`).
 
 ```json
-{"type":"message.send","id":10,"chat_id":"android:default","thread_id":null,
+{"type":"message.send","id":10,"chat_id":"default","thread_id":null,
  "payload":{"text":"/model qwen3-27b","reply_to":"m_9001","media_refs":["mu_1"],
             "auto_thread":false}}
 ```
@@ -383,8 +383,8 @@ Answer an interactive picker.
 
 ```json
 {"type":"channel.create","id":14,"payload":{"name":"Cron Reports","kind":"channel"}}
-{"type":"channel.rename","id":15,"chat_id":"android:chan_7","payload":{"name":"Reports"}}
-{"type":"channel.set_default","id":16,"chat_id":"android:chan_7","payload":{}}
+{"type":"channel.rename","id":15,"chat_id":"chan_7","payload":{"name":"Reports"}}
+{"type":"channel.set_default","id":16,"chat_id":"chan_7","payload":{}}
 ```
 
 `channel.delete` is a **hard delete**: the channel/thread row is removed from
@@ -396,7 +396,7 @@ removes its threads. The default channel cannot be deleted.
 
 ```json
 {"type":"search","id":17,"payload":{"query":"deploy","scope":"all"}}
-{"type":"search","id":18,"payload":{"query":"deploy","scope":"chat","chat_id":"android:chan_7","thread_id":null}}
+{"type":"search","id":18,"payload":{"query":"deploy","scope":"chat","chat_id":"chan_7","thread_id":null}}
 ```
 
 `scope` ∈ `all | chat`.
@@ -408,7 +408,7 @@ broadcasts to other devices (for multi-device ✓✓ sync). The app uses it to
 mark messages as read locally (✓✓ on user bubbles).
 
 ```json
-{"type":"read.receipt","payload":{"chat_id":"android:default","message_id":"m_9001"}}
+{"type":"read.receipt","payload":{"chat_id":"default","message_id":"m_9001"}}
 ```
 
 ### `history`
@@ -416,7 +416,7 @@ mark messages as read locally (✓✓ on user bubbles).
 Load a page of messages for a chat/thread (initial open, scroll-up pagination).
 
 ```json
-{"type":"history","id":20,"chat_id":"android:default","thread_id":null,
+{"type":"history","id":20,"chat_id":"default","thread_id":null,
  "payload":{"before_message_id":"m_8990","limit":50}}
 ```
 
@@ -433,7 +433,7 @@ message already gone (pruned by retention) still yields a `message.deleted`
 broadcast so live caches drop it.
 
 ```json
-{"type":"message.delete","id":30,"chat_id":"android:default","thread_id":null,
+{"type":"message.delete","id":30,"chat_id":"default","thread_id":null,
  "payload":{"message_ids":["m_9001","m_9002"]}}
 ```
 
@@ -458,7 +458,7 @@ Autocomplete for a typed `/prefix`.
 Stop the current agent turn (abort generation / tool execution).
 
 ```json
-{"type":"agent.stop","id":23,"chat_id":"android:default","thread_id":null,"payload":{}}
+{"type":"agent.stop","id":23,"chat_id":"default","thread_id":null,"payload":{}}
 ```
 
 ### `agent.steer`
@@ -466,7 +466,7 @@ Stop the current agent turn (abort generation / tool execution).
 Inject a steering message mid-turn (redirects the agent without a new turn).
 
 ```json
-{"type":"agent.steer","id":24,"chat_id":"android:default","thread_id":null,
+{"type":"agent.steer","id":24,"chat_id":"default","thread_id":null,
  "payload":{"text":"Actually, focus on the error case."}}
 ```