fix: nil-close bug, stale docs, dead code, and tracked binaries

- Fix potential nil file.Close() panic in devModePersist/devModeRemovePersisted
  by extracting loadDevModeMap/saveDevModeMap helpers with proper defer
- Remove tracked binaries (pathparams 10.8 MB, shake.db 22 MB) and consolidate
  .gitignore with a wildcard pattern covering all 19 examples
- Remove stale reaper reference in README (removed in dc56261), update example
  count from 14 to 19, fix OnChange debounce claim in docs
- Fix typos: "percist"→"persist", "percisted"→"persisted", "tmplates"→"templates"
- Remove dead code: commented import in signal_test.go, unnecessary fmt.Sprintf
  in computed.go, commented picocss imports and no-op Config calls in examples
- Replace go fmt with gofmt -l check in ci-check.sh to fail on unformatted code
  instead of silently reformatting

internal/examples/realtimechart/main.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"github.com/ryanhamamura/via"
-	// "github.com/go-via/via-plugin-picocss/picocss"
 	"github.com/ryanhamamura/via/h"
 )
 
@@ -16,9 +15,6 @@ func main() {
 	v.Config(via.Options{
 		LogLevel: via.LogLevelDebug,
 		DevMode:  true,
-		Plugins:  []via.Plugin{
-			// picocss.Default,
-		},
 	})
 
 	v.AppendToHead(