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/research/job-platform-analysis.md

@@ -0,0 +1,54 @@
+# Job Platform Analysis
+
+## Purpose
+
+Research job discovery opportunities.
+
+---
+
+# Possible Integrations
+
+Research:
+
+- Free APIs.
+- RSS feeds.
+- Public job sources.
+
+---
+
+# Desired Workflow
+
+Search jobs
+
+↓
+
+Save interesting jobs
+
+↓
+
+Create application
+
+↓
+
+Track progress
+
+---
+
+# Filters
+
+Potential:
+
+- Location.
+- Job title.
+- Industry.
+- Salary.
+- Remote.
+- Skills.
+
+---
+
+# Principle
+
+Job search enhances tracking.
+
+It does not replace job boards.