feat(backend): directory scanner — diff, error state, covers, cache sweep, redis lock

backend/internal/api/libraries.go

@@ -1,6 +1,7 @@
 package api
 
 import (
+	"context"
 	"io"
 	"log"
 	"net/http"
@@ -82,11 +83,15 @@ func (a *api) getLibrary(c *gin.Context) (store.Library, bool) {
 }
 
 func (a *api) scanLibrary(c *gin.Context) {
-	if _, ok := a.getLibrary(c); !ok {
+	lib, ok := a.getLibrary(c)
+	if !ok {
 		return
 	}
-	// Task 9 接线: go a.sc.ScanLibraryByID(...)
-	err(c, http.StatusNotImplemented, "not_ready", "scanner not wired yet")
+	if _, ok := a.libRoot(c, lib); !ok {
+		return
+	}
+	go a.sc.ScanLibraryByID(context.WithoutCancel(c), lib.ID)
+	c.JSON(http.StatusAccepted, gin.H{"accepted": true})
 }
 
 func (a *api) upload(c *gin.Context) {