feat: ADR-024 Contrastive CSI Embedding Model — all 7 phases (#52)

Full implementation of Project AETHER — Contrastive CSI Embedding Model.

## Phases Delivered
1. ProjectionHead (64→128→128) + L2 normalization
2. CsiAugmenter (5 physically-motivated augmentations)
3. InfoNCE contrastive loss + SimCLR pretraining
4. FingerprintIndex (4 index types: env, activity, temporal, person)
5. RVF SEG_EMBED (0x0C) + CLI integration
6. Cross-modal alignment (PoseEncoder + InfoNCE)
7. Deep RuVector: MicroLoRA, EWC++, drift detection, hard-negative mining, SEG_LORA

## Stats
- 276 tests passing (191 lib + 51 bin + 16 rvf + 18 vitals)
- 3,342 additions across 8 files
- Zero unsafe/unwrap/panic/todo stubs
- ~55KB INT8 model for ESP32 edge deployment

Also fixes deprecated GitHub Actions (v3→v4) and adds feat/* branch CI triggers.

Closes #50

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: Continuous Integration
 
 on:
   push:
-    branches: [ main, develop, 'feature/*', 'hotfix/*' ]
+    branches: [ main, develop, 'feature/*', 'feat/*', 'hotfix/*' ]
   pull_request:
     branches: [ main, develop ]
   workflow_dispatch:
@@ -25,7 +25,7 @@ jobs:
         fetch-depth: 0
 
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ env.PYTHON_VERSION }}
         cache: 'pip'
@@ -54,7 +54,7 @@ jobs:
       continue-on-error: true
 
     - name: Upload security reports
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       if: always()
       with:
         name: security-reports
@@ -98,7 +98,7 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
         cache: 'pip'
@@ -126,14 +126,14 @@ jobs:
         pytest tests/integration/ -v --junitxml=integration-junit.xml
 
     - name: Upload coverage reports
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         file: ./coverage.xml
         flags: unittests
         name: codecov-umbrella
 
     - name: Upload test results
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       if: always()
       with:
         name: test-results-${{ matrix.python-version }}
@@ -153,7 +153,7 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ env.PYTHON_VERSION }}
         cache: 'pip'
@@ -174,7 +174,7 @@ jobs:
         locust -f tests/performance/locustfile.py --headless --users 50 --spawn-rate 5 --run-time 60s --host http://localhost:8000
 
     - name: Upload performance results
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: performance-results
         path: locust_report.html
@@ -236,7 +236,7 @@ jobs:
         output: 'trivy-results.sarif'
 
     - name: Upload Trivy scan results
-      uses: github/codeql-action/upload-sarif@v2
+      uses: github/codeql-action/upload-sarif@v3
       if: always()
       with:
         sarif_file: 'trivy-results.sarif'
@@ -252,7 +252,7 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ env.PYTHON_VERSION }}
         cache: 'pip'
@@ -272,7 +272,7 @@ jobs:
         "
 
     - name: Deploy to GitHub Pages
-      uses: peaceiris/actions-gh-pages@v3
+      uses: peaceiris/actions-gh-pages@v4
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_dir: ./docs
@@ -286,7 +286,7 @@ jobs:
     if: always()
     steps:
     - name: Notify Slack on success
-      if: ${{ needs.code-quality.result == 'success' && needs.test.result == 'success' && needs.docker-build.result == 'success' }}
+      if: ${{ secrets.SLACK_WEBHOOK_URL != '' && needs.code-quality.result == 'success' && needs.test.result == 'success' && needs.docker-build.result == 'success' }}
       uses: 8398a7/action-slack@v3
       with:
         status: success
@@ -296,7 +296,7 @@ jobs:
         SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
 
     - name: Notify Slack on failure
-      if: ${{ needs.code-quality.result == 'failure' || needs.test.result == 'failure' || needs.docker-build.result == 'failure' }}
+      if: ${{ secrets.SLACK_WEBHOOK_URL != '' && (needs.code-quality.result == 'failure' || needs.test.result == 'failure' || needs.docker-build.result == 'failure') }}
       uses: 8398a7/action-slack@v3
       with:
         status: failure
@@ -307,18 +307,16 @@ jobs:
 
     - name: Create GitHub Release
       if: github.ref == 'refs/heads/main' && needs.docker-build.result == 'success'
-      uses: actions/create-release@v1
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      uses: softprops/action-gh-release@v2
       with:
         tag_name: v${{ github.run_number }}
-        release_name: Release v${{ github.run_number }}
+        name: Release v${{ github.run_number }}
         body: |
           Automated release from CI pipeline
-          
+
           **Changes:**
           ${{ github.event.head_commit.message }}
-          
+
           **Docker Image:**
           `${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.sha }}`
         draft: false