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/_archive/documentation-rules.md

@@ -0,0 +1,171 @@
+# Jobjakt Documentation Rules
+
+## Purpose
+
+This document defines how documentation in this repository should be created and maintained.
+
+Documentation is considered part of the product.
+
+---
+
+# Documentation Principles
+
+## Source of truth
+
+Product decisions:
+
+- Product documentation
+- ADRs
+
+Technical reality:
+
+- Codebase
+- Database
+- Configuration
+
+If documentation and code disagree:
+
+- Code represents current reality.
+- Documentation represents intended direction.
+
+The difference must be documented.
+
+---
+
+# Document Types
+
+## Product Documents
+
+Describe:
+
+- Why something exists.
+- User problems.
+- Expected behaviour.
+- Business goals.
+
+Examples:
+
+- Product vision.
+- User journeys.
+- Feature requirements.
+
+---
+
+## Technical Documents
+
+Describe:
+
+- How something works.
+- Architecture.
+- Implementation details.
+
+Examples:
+
+- API documentation.
+- Database models.
+- Services.
+
+---
+
+## Decision Records
+
+Architecture Decision Records explain important choices.
+
+Format:
+
+
+Context
+
+Decision
+
+Alternatives considered
+
+Consequences
+
+
+---
+
+# Required Document Sections
+
+Where relevant documents should include:
+
+## Purpose
+
+Why does this exist?
+
+## User Value
+
+What problem does this solve?
+
+## User Journey
+
+How does the user interact with it?
+
+## Requirements
+
+What must happen?
+
+## Non Requirements
+
+What should not happen?
+
+## Technical Notes
+
+Implementation considerations.
+
+## Future Considerations
+
+Possible expansion.
+
+## Open Questions
+
+Unknown decisions.
+
+---
+
+# AI Development Rules
+
+AI assistants must:
+
+- Read relevant documentation before coding.
+- Analyse existing implementation.
+- Avoid unnecessary rewrites.
+- Preserve existing functionality.
+- Update documentation after significant changes.
+
+---
+
+# Updating Documentation
+
+When implementing features:
+
+Update:
+
+- Relevant feature documentation.
+- Architecture documentation.
+- ADRs if decisions change.
+
+---
+
+# Accuracy
+
+Never invent:
+
+- Existing features.
+- Database fields.
+- APIs.
+- User behaviour.
+
+Separate:
+
+Fact:
+
+Something confirmed in code.
+
+Recommendation:
+
+Suggested improvement.
+
+Future idea:
+
+Possible later feature.