Watch: show subagent requests on the parent's card, and settle threads by swipe, Settle all and the thread screen

watch/README.md

@@ -38,7 +38,8 @@ register their token with the gateway as `production`, Debug builds as `sandbox`
 ## Demo mode
 
 `DemoGateway` serves fixture data shaped like the docs/api.md examples, and it reacts to writes:
-Allow moves a thread to working, a reply restarts a finished thread. The SwiftUI previews use it,
+Allow moves a thread to working, a reply restarts a finished thread, and Settle hides a thread from
+the feed. One card carries a subagent's request, so its Allow goes to the subagent's thread. The SwiftUI previews use it,
 the pairing screen has a "Try the demo" button, and launch arguments open a screen directly:
 
 ```sh
@@ -50,8 +51,9 @@ xcrun simctl launch <udid> org.gbrown.wristcode.watchkitapp -demo -host laptop
 xcrun simctl launch <udid> org.gbrown.wristcode.watchkitapp -demo -screen notifications          # notifications
 ```
 
-`screenshots/` holds the screens captured this way. The complication, the multi-select question and
-the status screens are rendered by `SnapshotTests` instead, which only run when given a directory:
+`screenshots/` holds the screens captured this way. The complication, the multi-select question, the
+status screens, the subagent card and thread, Recent with Settle all, and a finished thread with
+Settle are rendered by `SnapshotTests` instead, which only run when given a directory:
 
 ```sh
 TEST_RUNNER_WC_SCREENSHOT_DIR=$PWD/screenshots xcodebuild -scheme WristCode \
@@ -61,6 +63,17 @@ TEST_RUNNER_WC_SCREENSHOT_DIR=$PWD/screenshots xcodebuild -scheme WristCode \
 
 In demo mode the complication shows the demo counts too.
 
+## Subagents and settling
+
+A thread an agent started for another thread has no card of its own. When it waits on you, the
+gateway puts its request on the parent's card and names it in `via`. The card says "Subagent
+<title> wants to run:" or "asks:", and the parent's thread screen shows the request first, labeled
+"From subagent". Every answer goes to the subagent's thread.
+
+Settle clears a finished or failed thread from the feed, as in T3. Swipe a Recent row left, tap
+Settle all on the Recent header (completed threads only, failed ones stay), or tap Settle under
+Reply on the thread screen. A row leaves at once and comes back with the error if its call fails.
+
 ## Status and settings
 
 The gear at the top left of the feed opens the status overview (`GET /v1/status`). It leads with