feat(agent) multi-driver db monitoring, hot-plug config, release pipeline

internal/collectors/sqlite/sqlite.go

@@ -0,0 +1,30 @@
+package sqlite
+
+import (
+	"os"
+
+	"bugs.watch/agent/internal/aggregate"
+)
+
+// Collector reports the on-disk size of a SQLite database file.
+// No driver or connection is needed; we simply stat the file.
+// Failures are silently skipped.
+type Collector struct {
+	path string
+}
+
+func New(path string) *Collector {
+	return &Collector{path: path}
+}
+
+func (c *Collector) Name() string { return "sqlite" }
+
+func (c *Collector) Close() {}
+
+func (c *Collector) Collect(window *aggregate.Window) {
+	info, err := os.Stat(c.path)
+	if err != nil {
+		return
+	}
+	window.SetDBSizeBytes(uint64(info.Size()))
+}