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/future-features.md

@@ -0,0 +1,51 @@
+# Future Job Features
+
+Possible ideas:
+
+## Advanced Search
+
+- Job recommendations.
+- Saved searches.
+- Alerts.
+
+---
+
+## AI Matching
+
+Analyse:
+
+- User skills.
+- Job requirements.
+
+Suggest:
+
+- Match score.
+- Missing skills.
+- Improvement areas.
+
+---
+
+## Interview Management
+
+Support:
+
+- Preparation.
+- Questions.
+- Notes.
+- Feedback.
+
+---
+
+## Salary Tracking
+
+Potential:
+
+- Salary expectations.
+- Negotiations.
+- Market data.
+
+---
+
+# Priority Rule
+
+Only build features that improve the user's ability to find and secure employment.