chore: reliability and maintenance improvements

Host agent:
- Add SHA256 checksum verification for downloaded binaries
- Verify checksum file matches expected bundle filename

WebSocket:
- Add write failure tracking with graceful disconnection
- Increase write deadline to 30s for large state payloads
- Better handling for slow clients (Raspberry Pi, slow networks)

Monitoring:
- Remove unused temperature proxy imports
- Add monitor polling improvements
- Expand test coverage

Other:
- Update package.json dependencies
- Fix generate-release-notes.sh path handling
- Minor reporting engine cleanup

package.json

@@ -9,7 +9,9 @@
   },
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "prepare": "husky"
+    "prepare": "husky",
+    "mock:on": "sed -i 's/PULSE_MOCK_MODE=.*/PULSE_MOCK_MODE=true/' .env || echo 'PULSE_MOCK_MODE=true' >> .env",
+    "mock:off": "sed -i 's/PULSE_MOCK_MODE=.*/PULSE_MOCK_MODE=false/' .env || echo 'PULSE_MOCK_MODE=false' >> .env"
   },
   "repository": {
     "type": "git",
@@ -26,4 +28,4 @@
   "devDependencies": {
     "husky": "^9.1.7"
   }
-}
+}