Phase 2: core-crash from floret-kit; complete the core-time wiring

Adds crash reporting to Agendula by drawing the kit's new core-crash module
(first Android-library module in floret-kit), and finishes the core-time wiring
that a Phase 0 staging slip left uncommitted on main.

core-crash (NEW capability — Agendula had none):
- CrashReporter.install() in AgendulaApp captures uncaught exceptions on-device
  (allowlist-only report, chains to the platform handler, uploads nothing).
- MainActivity routes to a standalone CrashReportActivity on a startup crash-loop,
  and surfaces a single captured crash as a dialog on next launch; markHealthy on
  resume. App label + issue-tracker URL flow in via CrashConfig.
- Thin app-side CrashReportActivity uses AgendulaTheme; the reusable machinery
  (reporter, dialog, submit, config) lives in the kit. Submodule re-pinned to the
  core-crash kit commit.

Completes Phase 0 (was only partially committed in ec7b696):
- Repoint DayWindow + Instant formatting imports to de.jeanlucmakiola.floret.time
  (the app copies were deleted in ec7b696 but the imports/includeBuild/dependency
  were never staged, leaving main non-building).
- settings.gradle.kts includeBuild("floret-kit"); app depends on core-time.

Also fixes the CI checkout YAML: the submodules block was mis-indented under
'uses:' (invalid step mapping) — dedented to a proper sibling.

Clean composite build + unit tests + lintDebug + debug assemble green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/res/values/strings.xml

@@ -176,6 +176,7 @@
     <string name="settings_report_problem">Report a problem</string>
     <string name="settings_report_problem_hint">Open the issue tracker</string>
     <string name="about_source_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/agendula</string>
+    <string name="crash_report_issue_title">Crash report</string>
     <string name="report_issue_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/agendula/issues/new</string>
     <string name="about_license_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/agendula/src/branch/main/LICENSE</string>
     <string name="about_support_url" translatable="false">https://ko-fi.com/jeanlucmakiola</string>