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/jobs/job-search.md

@@ -0,0 +1,55 @@
+# Job Search Enhancement
+
+## Purpose
+
+Help users discover opportunities.
+
+This is not the primary product.
+
+---
+
+# Ideal Flow
+
+Search jobs
+
+↓
+
+Find interesting role
+
+↓
+
+Import into Jobjakt
+
+↓
+
+Track application
+
+---
+
+# Potential Filters
+
+- Job title.
+- Keywords.
+- Location.
+- Remote.
+- Industry.
+- Salary.
+- Experience level.
+
+---
+
+# Integrations
+
+Research available:
+
+- Free APIs.
+- Public feeds.
+- Job providers.
+
+---
+
+# Rules
+
+Do not become another job board.
+
+The value is organisation.