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/career/future-features.md

@@ -0,0 +1,48 @@
+# Future Career Features
+
+Potential additions:
+
+## LinkedIn Integration
+
+Generate:
+
+- About section.
+- Experience summaries.
+
+---
+
+## Interview Preparation
+
+Generate:
+
+- Questions.
+- Answers.
+- Preparation plans.
+
+---
+
+## Skill Analysis
+
+Compare:
+
+Career profile
+
+against
+
+Job requirements.
+
+---
+
+## Career Planning
+
+Support:
+
+- Learning paths.
+- Skill gaps.
+- Goals.
+
+---
+
+# Priority
+
+Only add features that improve career outcomes.