chore: add Open Collective funding config and support section

- Add .github/FUNDING.yml for GitHub sponsor button
- Add Support section to README with Open Collective link
- Add coverage script (vitest --coverage)
- No functional code changes

Author: rootvector2

.github/workflows/FUNDING.yml

@@ -0,0 +1 @@
+open_collective: SmartRetry

README.md

@@ -260,3 +260,19 @@ npm run build
 ## License
 
 MIT
+
+## Support
+
+SmartRetry is maintained as open-source infrastructure software.
+
+If it provides value in your projects, consider supporting its long-term maintenance:
+
+👉 https://opencollective.com/SmartRetry
+
+Contributions help fund:
+- Ongoing maintenance and bug fixes
+- Test infrastructure and CI
+- Documentation improvements
+- Performance validation and benchmarking
+
+All development remains public and transparent.

package.json

@@ -32,6 +32,7 @@
     "test": "vitest run",
     "test:watch": "vitest",
     "typecheck": "tsc --noEmit",
+    "coverage": "vitest run --coverage",
     "prepublishOnly": "npm run build"
   },
   "keywords": [