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/product/non-goals.md

@@ -0,0 +1,66 @@
+# Product Non Goals
+
+## Purpose
+
+Defines what Jobjakt should avoid becoming.
+
+---
+
+# Not A Job Board
+
+Jobjakt should not compete directly with:
+
+- LinkedIn Jobs.
+- Indeed.
+- Finn.
+- Other job marketplaces.
+
+Job discovery is an enhancement.
+
+The main value is managing opportunities.
+
+---
+
+# Not Only A CV Builder
+
+CV functionality is important but secondary.
+
+The product is not:
+
+"Create a CV"
+
+The product is:
+
+"Manage your career and applications."
+
+---
+
+# Not A Recruiter Platform
+
+Recruiter tools are not currently a priority.
+
+Future consideration only.
+
+---
+
+# Not A Generic AI Chatbot
+
+AI features should be embedded into workflows.
+
+Avoid:
+
+- Empty chat experiences.
+- AI without context.
+- Generic assistants.
+
+---
+
+# Not Feature Overload
+
+Do not add features simply because competitors have them.
+
+Every feature should improve:
+
+- Finding jobs.
+- Applying.
+- Managing careers.