ci: add HTTP API test toggle to workflow_dispatch

Adds enable_http_api_tests boolean input to CI workflow for remote
testing of HTTP REST API endpoints via GitHub Actions.

Changes:
- Add enable_http_api_tests workflow_dispatch input (default: false)
- Add conditional HTTP API test step to test job
- Runs scripts/agents/test-http-api.sh when enabled

Usage:
  gh workflow run ci.yml --ref develop -f enable_http_api_tests=true

Enables CI validation of HTTP API without requiring local builds or
network access for sandbox environments.

Co-Authored-By: Gemini <noreply@google.com>
Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -38,6 +38,11 @@ on:
         required: false
         default: false
         type: boolean
+      enable_http_api_tests:
+        description: 'Enable HTTP API tests'
+        required: false
+        default: false
+        type: boolean
 
 env:
   BUILD_TYPE: ${{ github.event.inputs.build_type || 'RelWithDebInfo' }}
@@ -148,6 +153,10 @@ jobs:
           test-type: unit
           preset: ${{ matrix.preset }}
 
+      - name: Run HTTP API tests
+        if: github.event.inputs.enable_http_api_tests == 'true'
+        run: scripts/agents/test-http-api.sh
+
   windows-agent:
     name: "Windows Agent (Full Stack)"
     runs-on: windows-2022