fix: use saveable repository list keys

app/src/main/java/com/ubisam/ubgitea/feature/repositories/RepositoryListScreen.kt

@@ -223,7 +223,7 @@ private fun RepositoryContent(
         if (state.mode == RepositoryListMode.ALL && state.organizations.isNotEmpty()) {
             item { OrganizationFilterRow(state.organization, state.organizations, onSelectOrganization) }
         }
-        items(state.repositories, key = { it.coordinates }) { repository ->
+        items(state.repositories, key = { repositoryLazyListKey(it.coordinates) }) { repository ->
             Column(
                 Modifier
                     .fillMaxWidth()
@@ -265,6 +265,9 @@ private fun RepositoryContent(
     }
 }
 
+internal fun repositoryLazyListKey(coordinates: RepositoryCoordinates): String =
+    "${coordinates.owner}/${coordinates.name}"
+
 @Composable
 private fun OrganizationFilterRow(
     selected: String?,

app/src/test/java/com/ubisam/ubgitea/feature/repositories/RepositoryListScreenTest.kt

@@ -0,0 +1,23 @@
+package com.ubisam.ubgitea.feature.repositories
+
+import com.ubisam.ubgitea.domain.model.RepositoryCoordinates
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Test
+
+class RepositoryListScreenTest {
+    @Test
+    fun `lazy list key is a stable saveable string`() {
+        val coordinates = RepositoryCoordinates.of("team", "mobile")
+
+        assertEquals("team/mobile", repositoryLazyListKey(coordinates))
+    }
+
+    @Test
+    fun `lazy list keys distinguish the same repository name under different owners`() {
+        val first = repositoryLazyListKey(RepositoryCoordinates.of("team-a", "mobile"))
+        val second = repositoryLazyListKey(RepositoryCoordinates.of("team-b", "mobile"))
+
+        assertNotEquals(first, second)
+    }
+}

docs/development-log.md

@@ -305,3 +305,11 @@ This is the append-only implementation and handoff record shared by Codex and Cl
 - Known limitations: Physical-device callback verification is still required. Gitea star/unstar mutation is intentionally unavailable with the restored read-only token.
 - Next recommended task: Install the rebuilt debug APK, clear UBGitea app data once, complete login approval, and verify repository loading.
 - Next owner: Human product owner for device verification, then Claude for review.
+
+## 2026-08-26 — TASK-020 repository-list crash fix
+
+- Agent and role: Codex, incident resolver.
+- Root cause: The repository `LazyColumn` used `RepositoryCoordinates` as its item key. Compose passes lazy-item keys to Android saved state, but this domain object is not a `Bundle`-saveable type, causing an uncaught main-thread `IllegalArgumentException` as soon as authenticated rows rendered.
+- Implementation: Repository rows now use the stable string key `owner/name`; repository components cannot contain `/`, so the key remains unique across owners and repositories while being Android-saveable.
+- Regression coverage: Added tests for deterministic key encoding and for equal repository names under different owners.
+- Checks: Focused tests and `assembleDebug testDebugUnitTest lintDebug` passed. The APK installed wirelessly over the authenticated device, `MainActivity` remained resumed, and the cleared crash buffer stayed empty. Final visual inspection is pending because the handset locked.

tasks/020-repository-list-saveable-key.md

@@ -0,0 +1,38 @@
+# TASK-020: Prevent repository-list crash after login
+
+Status: implemented; unlocked-screen confirmation pending
+Owner: Codex
+Reviewer: Claude
+
+## Outcome
+
+After a successful OAuth login, the repository list renders without terminating the app, and subsequent launches remain usable.
+
+## Risk
+
+Compose lazy-list item keys participate in saved UI state on Android. A key that cannot be stored in a `Bundle` throws on the main thread while the list is composed.
+
+## Writable paths
+
+- `app/src/main/java/com/ubisam/ubgitea/feature/repositories/RepositoryListScreen.kt`
+- matching unit tests
+- this task file and `docs/development-log.md`
+
+## Acceptance criteria
+
+- [x] Repository rows use a unique, stable, Android-saveable key.
+- [x] A regression test covers repositories with the same name under different owners.
+- [x] Debug build, unit tests, and Android lint pass.
+- [ ] The rebuilt APK launches and renders the authenticated repository list on the physical device.
+- [x] Repository secret-pattern scan reports no credential material.
+
+## Incident evidence
+
+Physical-device crash buffer on 2026-08-26 reported `IllegalArgumentException: Type of the key RepositoryCoordinates(...) is not supported` from `SaveableStateHolderImpl.SaveableStateProvider`, originating while the repository `LazyColumn` was composed.
+
+## Verification evidence
+
+- Focused regression tests passed.
+- `assembleDebug testDebugUnitTest lintDebug` passed.
+- The rebuilt APK installed over the existing authenticated installation successfully; the app process remained alive with `MainActivity` resumed and the post-launch crash buffer empty.
+- The handset locked before the rendered repository rows could be inspected, so visual confirmation remains pending.