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/company-management.md

@@ -0,0 +1,58 @@
+# companies
+
+TODO: Complete documentation.
+# Company Management
+
+## Purpose
+
+Companies should be reusable objects.
+
+---
+
+# Features
+
+Store:
+
+- Name.
+- Website.
+- Location.
+- Industry.
+- Notes.
+
+---
+
+# Relationships
+
+One company:
+
+↓
+
+Many jobs
+
+↓
+
+Many applications
+
+---
+
+# Automatic Creation
+
+When importing jobs:
+
+If company exists:
+
+Reuse.
+
+If not:
+
+Create automatically.
+
+---
+
+# Future
+
+Possible:
+
+- Company research.
+- Reviews.
+- Hiring insights.