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/technical/docker.md

@@ -0,0 +1,51 @@
+# Docker
+
+## Purpose
+
+Maintain consistent environments.
+
+---
+
+# Requirements
+
+Containers should:
+
+- Have clear names.
+- Use health checks.
+- Log correctly.
+
+---
+
+# Images
+
+Prefer:
+
+- Official images.
+- Pinned versions.
+
+---
+
+# Volumes
+
+Important data must use persistent storage.
+
+---
+
+# Production
+
+Monitor:
+
+- Container health.
+- Memory usage.
+- Disk usage.
+- Restarts.
+
+---
+
+# Common Issues
+
+Investigate:
+
+- Container crashes.
+- Storage exhaustion.
+- Network issues.