fix(mobile): keep the two advisory task probes total so a nullish payload cannot unhydrate the screen

`preflight.check` and `linear.status` are read under `success-result-or-skip` and documented as
advisory. That policy accepts an envelope whose `result` is absent or null, then asks the reader to
decode it; a `looseObject` refuses, the throw leaves the reader, and the caller's catch discards the
entire hydration. The corpus records the difference: on the `result-absent` and `result-null`
partitions main hydrates the Tasks screen and lists one provider, and the checked readers left it
unhydrated with no providers.

`.catch` restores main's answer exactly. Every consumer guards to the leaf and compares to `true`,
so absence, null and a garbage payload have always meant "not installed" and "not connected".

Four cases pin it, and removing either catch fails all four.

Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb

mobile/src/tasks/task-runtime-reply-schema.test.ts

@@ -87,6 +87,24 @@ describe('the two advisory probes', () => {
       gh: { installed: true, authenticated: true }
     })
   })
+
+  // `success-result-or-skip` accepts an envelope whose `result` is absent or null and then asks
+  // the reader to decode it, so a refusal here throws out of the caller's whole hydration. Main
+  // hydrated on both of these replies; the recorded settings.task-hydration and
+  // settings.workspace-context partitions are what caught the difference.
+  it.each([
+    ['absent', undefined],
+    ['null', null],
+    ['a bare string', 'preflight'],
+    ['an array', []]
+  ])('reads a %s payload as "nothing advertised" rather than refusing it', (_label, reply) => {
+    const preflight = taskPreflightSchema.safeParse(reply)
+    expect(preflight.success).toBe(true)
+    expect(preflight.success && preflight.data.glab?.installed).toBeUndefined()
+    const linear = taskLinearStatusSchema.safeParse(reply)
+    expect(linear.success).toBe(true)
+    expect(linear.success && linear.data.connected).toBeUndefined()
+  })
 })
 
 describe('the three preference writes', () => {

mobile/src/tasks/task-runtime-reply-schema.ts

@@ -64,13 +64,21 @@ export const taskUiStateSchema = z
  * (use-mobile-tasks-runtime-hydration.tsx:295, mobile-home-host-requests.ts:95) and the
  * `readProbeMember` pair in use-new-workspace-runtime-context.ts:92. `git` and `gh` are declared
  * non-optional by PreflightStatus but no mobile consumer reads them, so they pass through.
+ *
+ * Total on purpose. This read is advertised as advisory, but `success-result-or-skip` accepts an
+ * envelope whose `result` is absent or null and then asks the reader to decode it, and a refusal
+ * there throws out of the whole hydration -- the corpus records main hydrating the Tasks screen on
+ * that reply and this reader leaving it unhydrated. `.catch` restores main's answer exactly,
+ * because every consumer guards to the leaf and reads absence as "not installed".
  */
-export const taskPreflightSchema = z.looseObject({
-  glab: salvagedOptional(
-    'glab',
-    z.looseObject({ installed: salvagedOptional('installed', z.boolean()) })
-  )
-})
+export const taskPreflightSchema = z
+  .looseObject({
+    glab: salvagedOptional(
+      'glab',
+      z.looseObject({ installed: salvagedOptional('installed', z.boolean()) })
+    )
+  })
+  .catch({ glab: undefined })
 
 /**
  * Whether Linear is connected.
@@ -80,10 +88,15 @@ export const taskPreflightSchema = z.looseObject({
  * `false` already mean the same thing and nothing is required. `workspaces` is not declared: the
  * picker reads it through a different operation on this same method, and listing a member ahead of
  * a reader is how a schema starts refusing replies no consumer here would have noticed.
+ *
+ * Total for the same reason as the preflight read above: absence and `false` already mean the same
+ * thing here, so a nullish payload must read as "not connected" rather than throw.
  */
-export const taskLinearStatusSchema = z.looseObject({
-  connected: salvagedOptional('connected', z.boolean())
-})
+export const taskLinearStatusSchema = z
+  .looseObject({
+    connected: salvagedOptional('connected', z.boolean())
+  })
+  .catch({ connected: undefined })
 
 /**
  * The three writes whose reply body no call site reads.