Prepare project for pipeline takeover: task tracker, UX doc, CLAUDE.md pointers

Adds docs/tasks/ (16 epics + 102 stories converted to task/subtask files with
statuses.md as the new status source of truth) and docs/ux-design.md
(retrospective design-system reference), and points CLAUDE.md at them.
docs/prd.md and docs/architecture.md are kept as BMAD wrote them; the legacy
docs/stories/, docs/epics/, docs/qa/gates/ and .bmad-core/ stay in place as
historical/traceability records, superseded but not deleted.

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

docs/tasks/4.md

@@ -0,0 +1,21 @@
+---
+id: 4
+title: 4 Case Timeline System
+status: Ready for Dev
+date: 2026-09-27
+---
+
+## Description
+
+Lets the admin create and maintain one-way, text-only case timelines per client (multiple timelines per client, active/archived states), with clients able to view (read-only) their timelines and receive email notifications on updates.
+
+## Acceptance Criteria
+
+- [ ] Admin can create unlimited timelines per client
+- [ ] Admin can add text updates to timelines
+- [ ] Admin can edit existing updates
+- [ ] Admin can archive/unarchive timelines
+- [ ] Clients can view their timelines (read-only)
+- [ ] Clients notified via email on updates
+- [ ] Update history with timestamps preserved
+- [ ] Clear visual distinction between active/archived