Rename project to GoSentry

Rename the application, Go module path, command package, build artifacts, resource script, and embedded icon assets from PySentry/pysentry to GoSentry/gosentry.

Move portable settings to gosentry.yaml while reading legacy pysentry.yaml during the transition, then rewrite settings under the new name.

Update Windows and Linux autostart integration to use GoSentry names while cleaning up legacy PySentry registry, desktop-entry, and systemd artifacts.

Refresh README, architecture notes, roadmap, changelog, and release examples for version 0.3.0.

src/core/runner.go

@@ -94,7 +94,7 @@ func CleanupLogs(logsDir string, maxFiles int, maxAgeDays int) error {
 	var logs []logFile
 	cutoff := time.Now().AddDate(0, 0, -maxAgeDays)
 	for _, entry := range entries {
-		// Only PySentry run logs are managed here. Directories and non-.log files
+		// Only GoSentry run logs are managed here. Directories and non-.log files
 		// are intentionally ignored so the user can keep notes or other artifacts
 		// in the same folder without the cleanup policy deleting them.
 		if entry.IsDir() || !strings.HasSuffix(strings.ToLower(entry.Name()), ".log") {