docs: reorganize tree, restore architecture + research from archive, add Phase 0 reports

Active docs/ was stub scaffolding while the real docs sat in docs/_archive/.
Restore and correct them, and record the Phase 0 work.

- docs/architecture/current.md: verified system map (from archived SYSTEM_OVERVIEW,
  9 corrections against code).
- docs/research/competitors.md: sourced competitor analysis (from archived
  PRODUCT_RESEARCH, feature matrix corrected).
- docs/decisions/ADR-002-job-application-model.md: the Job/JobApplication split.
- docs/application-discovery-report.md, docs/implementation-roadmap.md,
  docs/phase-0-foundation-report.md, docs/career-workspace-branch-assessment.md.
- Remove 10 zero-byte placeholder files that advertised content that never existed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/ux/dashboard.md

@@ -0,0 +1,73 @@
+# Dashboard Experience
+
+## Purpose
+
+The dashboard is the user's command centre.
+
+It should answer:
+
+"What should I do next?"
+
+---
+
+# Primary Information
+
+Display:
+
+## Application Overview
+
+Examples:
+
+- Active applications.
+- Interviews.
+- Pending follow-ups.
+- Recent activity.
+
+---
+
+## Upcoming Actions
+
+Examples:
+
+- Follow up with company.
+- Prepare interview.
+- Complete application.
+
+---
+
+## Progress
+
+Examples:
+
+- Applications this month.
+- Interview rate.
+- Response rate.
+
+---
+
+# Dashboard Actions
+
+Primary action:
+
+Add Job
+
+Secondary:
+
+- Update CV.
+- Review follow-ups.
+- Search jobs.
+
+---
+
+# Design Direction
+
+Inspired by:
+
+- Notion.
+- Linear.
+
+Avoid:
+
+- Dense dashboards.
+- Too many cards.
+- Information overload.