Refactor annotation tool from WPF desktop app to .NET API

Replace the WPF desktop application (Azaion.Suite, Azaion.Annotator,
Azaion.Common, Azaion.Inference, Azaion.Loader, Azaion.LoaderUI,
Azaion.Dataset, Azaion.Test) with a standalone .NET Web API in src/.

Made-with: Cursor

.cursor/skills/research/templates/solution_draft_mode_b.md

@@ -0,0 +1,40 @@
+# Solution Draft
+
+## Assessment Findings
+
+| Old Component Solution | Weak Point (functional/security/performance) | New Solution |
+|------------------------|----------------------------------------------|-------------|
+| [old] | [weak point] | [new] |
+
+## Product Solution Description
+[Short description. Brief component interaction diagram. Written as if from scratch — no "updated" markers.]
+
+## Architecture
+
+[Architecture solution that meets restrictions and acceptance criteria.]
+
+### Component: [Component Name]
+
+| Solution | Tools | Advantages | Limitations | Requirements | Security | Performance | Fit |
+|----------|-------|-----------|-------------|-------------|----------|------------|-----|
+| [Option 1] | [lib/platform] | [pros] | [cons] | [reqs] | [security] | [perf] | [fit assessment] |
+| [Option 2] | [lib/platform] | [pros] | [cons] | [reqs] | [security] | [perf] | [fit assessment] |
+
+[Repeat per component]
+
+## Testing Strategy
+
+### Integration / Functional Tests
+- [Test 1]
+- [Test 2]
+
+### Non-Functional Tests
+- [Performance test 1]
+- [Security test 1]
+
+## References
+[All cited source links]
+
+## Related Artifacts
+- Tech stack evaluation: `_docs/01_solution/tech_stack.md` (if Phase 3 was executed)
+- Security analysis: `_docs/01_solution/security_analysis.md` (if Phase 4 was executed)