The recovery button did not recover, and half the text went black

Two bugs from testing on the emulator, one of them mine from this morning.

## "Erase and start fresh" erased nothing

🔴 The `VaultUnreadable` screen — shown when the keys on this phone cannot be
opened — offered exactly one action, and it called `model::signOut`. `signOut`
defaults to `erasingDevice = false`: the door that deliberately KEEPS the device
so coming back is silent. So it set the phase to SignedOut, left the unreadable
vault exactly where it was, and the next `restore()` opened it, failed again,
and came straight back to the same screen.

⚠️ It looked like it worked, because the screen changed. That is the whole
problem with a recovery action that does not recover: the feedback IS the claim,
and the person only finds out when they try to sign in and land back where they
started. Which is what happened, twice, to the person testing it.

`discardUnreadableVault()` destroys the vault, opens a fresh one, and lands on
sign-in with a sentence saying what happened and that contacts will see the
security keys change. Deliberately NOT `signOut(erasingDevice = true)`, which
would also have worked: that path first tries to revoke the device on the relay
using a session that by definition does not exist here, and its comments are
about handing a phone on. The keys are already lost; the only question is
whether the app can get past them.

Three tests, in the same source-scan shape as `DestructiveLabelsTest`. Falsified:
putting `model::signOut` back fails with the reason spelled out.

## Black text on the dark ground

🔴 `Surface(color = Color.Transparent)` with no `contentColor`. Material derives
it with `contentColorFor(color)`, which has no answer for Transparent and
returns Unspecified — so `LocalContentColor` falls back to its own default,
which is BLACK. Every `Text` that does not name a colour of its own drew black
on the dark ground.

⚠️ It read as "some of the text is hard to read" rather than as a broken theme,
because everything that DOES set a colour was fine and only the inheriting ones
went dark. That is what made it easy to ship: the screens I looked at longest
were the ones that name their colours.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/src/main/kotlin/io/flamenet/messenger/app/MainActivity.kt

@@ -118,6 +118,19 @@ class MainActivity : androidx.fragment.app.FragmentActivity() {
                 // default container colour paints straight over it.
                 Surface(
                     color = androidx.compose.ui.graphics.Color.Transparent,
+                    // 🔴 **`contentColor` MUST be set when `color` is
+                    // Transparent.** Material derives it with
+                    // `contentColorFor(color)`, which has no answer for
+                    // Transparent and returns Unspecified — so `LocalContentColor`
+                    // falls back to its own default, which is BLACK. Every
+                    // `Text` that does not name a colour of its own then draws
+                    // black on the dark ground.
+                    //
+                    // It looked like "some of the text is hard to read" rather
+                    // than like a broken theme, because the many places that DO
+                    // set a colour were fine and only the inheriting ones went
+                    // dark.
+                    contentColor = Palette.Ink,
                     modifier = Modifier.fillMaxSize().background(groundBrush()),
                 ) {
                     // 🔴 **The gate is around Root, not inside it.** Drawn over
@@ -915,7 +928,12 @@ private fun ColumnScope.VaultUnreadable(
         "Starting fresh publishes a new device. Everyone you talk to will see " +
             "\"security keys changed\", so tell them to expect it.",
     )
-    Button(onClick = model::signOut, modifier = Modifier.testTag("start-fresh")) {
+    // 🔴 `discardUnreadableVault`, NOT `signOut`. `signOut()` defaults to
+    // keeping the device, so it left the unreadable vault in place and the next
+    // restore came straight back here — the only button on a dead-end screen
+    // did nothing but redraw it.
+    Button(onClick = model::discardUnreadableVault,
+           modifier = Modifier.testTag("start-fresh")) {
         Text("Erase and start fresh")
     }
 }

app/src/main/kotlin/io/flamenet/messenger/app/MessengerViewModel.kt

@@ -3726,6 +3726,35 @@ class MessengerViewModel(app: Application) : AndroidViewModel(app) {
      * ⚠️ Keeping the keys does not leave the mailbox reachable: a relay token
      * is minted against the account credential, which this clears either way.
      */
+    /**
+     * Throw away a vault that cannot be opened, so sign-in is possible again.
+     *
+     * 🔴 **The "Erase and start fresh" button used to call `signOut()`, which
+     * erases nothing.** `signOut` defaults to `erasingDevice = false` — the
+     * door that deliberately KEEPS the device so coming back is silent — so it
+     * set the phase to SignedOut and left the unreadable vault exactly where it
+     * was. The next `restore()` opened it, failed again, and went straight back
+     * to VaultUnreadable. The one button on a dead-end screen was a loop.
+     *
+     * ⚠️ Not `signOut(erasingDevice = true)` either, though that would have
+     * worked. That path first tries to revoke the device on the relay using a
+     * session that by definition does not exist here, and its comments are
+     * about handing a phone on. This is a different situation: the keys are
+     * already lost, and the only question is whether the app can get past them.
+     */
+    fun discardUnreadableVault() = viewModelScope.launch {
+        polling?.cancel()
+        polling = null
+        session = null
+        withContext(Dispatchers.IO) { runCatching { KeystoreVault.destroy(getApplication()) } }
+        identity = null
+        vault = KeystoreVault.open(getApplication())
+        _phase.value = Phase.SignedOut(
+            error = "The keys stored on this phone could not be opened, so they have "
+                + "been cleared. Signing in registers this phone as a new device — "
+                + "your contacts will see that your security keys changed.")
+    }
+
     fun signOut(erasingDevice: Boolean = false) = viewModelScope.launch {
         polling?.cancel()
         polling = null