docs: initial architecture, roadmap, readme for ntfy-bridge

- README.md: project overview, quickstart, sources summary
- ARCHITECTURE.md: complete architecture, data flow, project structure
- ROADMAP.md: 5-phase development plan (v0.1.0 → v0.5.0+)
- CONTRIBUTING.md: dev setup, conventions, how to add a source
- ntfy-bridge.example.yaml: fully documented configuration template
- scripts/example-cron-disk.sh: example cron script → ntfy-bridge

.gitignore

@@ -0,0 +1,28 @@
+# ntfy-bridge
+
+# Binary
+ntfy-bridge
+ntfy-bridge.exe
+ntfy-bridge-mac
+
+# V build artifacts
+.vmodules/
+*.o
+*.obj
+*.exe
+*.so
+*.dylib
+
+# Config (contains secrets — use example as template)
+ntfy-bridge.yaml
+*.local.yaml
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db