test(activation): add Maestro E2E coverage for the activation flow

Adds deterministic end-to-end coverage for first-open -> telemetry consent
-> server URL entry -> connect -> send first message -> receive reply,
targeting the 0%-7-day-retention investigation (GitHub issue #76).

- tests/fixtures/mock-opencode-server.ts: dependency-free HTTP+SSE stub
  matching the REAL client protocol (src/lib/sdk.ts) — REST + a single
  long-lived GET /global/event SSE stream, no WebSocket. Supports a
  --fail-auth mode that 401s every request to exercise the connect-time
  auth-failure class.
- .maestro/flows/activation-positive.yaml: consent -> quick connect ->
  new session -> send message -> assert streamed reply renders, with a
  screenshot at every step (positive-S1..S8).
- .maestro/flows/activation-negative-401.yaml: same setup against the
  --fail-auth server, asserts Quick Connect's existing "Connection Failed"
  alert is shown (not silently swallowed) and that the connection is not
  saved. Flags in comments that Advanced-mode Save (handleAdvancedSave)
  still has no testConnection() check and is a known, uncovered gap.
- testID props added (no restructuring) to the screens/components the
  flows drive: TelemetryConsentModal, connection/add.tsx, tabs/index.tsx,
  session/[id].tsx, MessageBubble.
- .github/workflows/activation-e2e.yml: new CI job — Android emulator via
  reactivecircus/android-emulator-runner, builds the debug-signed APK,
  starts both mock server instances, runs both Maestro flows, uploads
  screenshots via actions/upload-artifact. Kept separate from the existing
  vision-driven cua-smoke.yml, which needs a live server + LLM and isn't
  suited to tight deterministic regression assertions.
- .gitignore: Maestro takeScreenshot output is never committed.

Verified locally: mock server exercised standalone via curl (health,
project/current, path, session create, SSE event ordering, message
persistence) in both normal and --fail-auth modes; both Maestro flow
files validated as well-formed YAML; tsc --noEmit clean on all changed
files. No lint script exists in this repo (N/A). Full emulator execution
was not run — no Android SDK/emulator available in this environment.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NJKAQ6HAikWGQK7PGZ5Y4E

app/connection/add.tsx

@@ -177,6 +177,7 @@ export default function AddConnectionScreen() {
             autoCapitalize="none"
             autoCorrect={false}
             keyboardType="url"
+            testID="connect-ip-input"
           />
           <Text style={[styles.ipColon, isDark && styles.textDark]}>:</Text>
           <TextInput
@@ -186,6 +187,7 @@ export default function AddConnectionScreen() {
             value={port}
             onChangeText={setPort}
             keyboardType="number-pad"
+            testID="connect-port-input"
           />
         </View>
 
@@ -208,6 +210,7 @@ export default function AddConnectionScreen() {
           value={password}
           onChangeText={setPassword}
           secureTextEntry
+          testID="connect-password-input"
         />
         <Text style={[styles.usernameHint, isDark && styles.hintDark]}>
           Username defaults to <Text style={styles.code}>opencode</Text>. Custom username? Use{" "}
@@ -222,6 +225,7 @@ export default function AddConnectionScreen() {
           style={[styles.connectButton, isDark && styles.connectButtonDark]}
           onPress={handleQuickConnect}
           disabled={isConnecting}
+          testID="connect-submit-button"
         >
           {isConnecting ? (
             <ActivityIndicator size="small" color={isDark ? "#0a0a0a" : "#ffffff"} />