Add missing manifest icons and PoC documentation

- Add emoji icon field to hello-dashboard, icd-test-runner,
  sdk-test-runner, and team-activity-log manifests
- Create README.md for tasks and schedules packages marking them
  as Proof of Concept with documented graduation criteria

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/schedules/README.md

@@ -0,0 +1,22 @@
+# Schedules
+
+**Status: Proof of Concept**
+
+Schedule management surface wrapping the kernel cron API. Ships with
+core for SDK validation purposes, not as a permanent commitment.
+
+## Purpose
+
+Provides a management UI for user-created scheduled tasks (cron). Proves
+that kernel APIs can be wrapped by extension surfaces without
+special-casing.
+
+## Graduation Criteria
+
+To become a permanent core package, schedules must meet:
+
+1. **Cron expression builder** — visual UI for building cron expressions
+2. **Execution history** — log viewer with output and error details
+3. **Error alerting** — notification on failed runs
+4. **Test coverage** — API contract tests in the ICD test runner
+5. **Timezone-aware display** — show next run in user's local timezone