refactor(handlers): update all handlers for Echo v5 compatibility

Update all handler functions to use *echo.Context (pointer) instead of echo.Context (value) as required by Echo v5.

Changes across all handler files:
- analytics.go: Update handler signatures
- auth.go: Update authentication handler signatures
- book_matching.go: Update matching handler signatures
- collections.go: Update collection handler signatures
- collections_preview_test.go: Update test signatures
- commonhandlers.go: Update common handler signatures
- conflicts.go: Update conflict handler signatures
- context.go: Update context handler signatures
- dashboard.go: Update dashboard handler signatures
- devices.go: Update device handler signatures
- jobs.go: Update job handler signatures
- kobo.go: Update Kobo handler signatures
- koreader.go: Update Koreader handler signatures
- library.go: Update library handler signatures
- matching.go: Update matching handler signatures
- media.go: Update media handler signatures
- opds.go: Update OPDS handler signatures
- progress.go: Update progress handler signatures
- queue.go: Update queue handler signatures
- refresh_token.go: Update token handler signatures
- scanner.go: Update scanner handler signatures
- sidecar.go: Update sidecar handler signatures
- sync.go: Update sync handler signatures
- system_settings.go: Update settings handler signatures
- websocket.go: Update WebSocket handler signatures

All handlers now properly implement Echo v5's pointer-based context pattern.
This change is necessary for type safety and compatibility with Echo v5's
improved context handling and WebSocket support.

internal/handlers/jobs.go

@@ -4,7 +4,7 @@ import (
 	"net/http"
 
 	"github.com/google/uuid"
-	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v5"
 
 	"bookhoard/internal/database"
 	"bookhoard/internal/services"
@@ -23,7 +23,7 @@ func NewJobsHandler(db *database.Queries, worker *services.Worker) *JobsHandler
 }
 
 // CreateJob creates a new job based on type
-func (h *JobsHandler) CreateJob(c echo.Context) error {
+func (h *JobsHandler) CreateJob(c *echo.Context) error {
 	var req struct {
 		Type   string                 `json:"type"`
 		Params map[string]interface{} `json:"params"`
@@ -73,7 +73,7 @@ func (h *JobsHandler) CreateJob(c echo.Context) error {
 }
 
 // GetJobStatus returns the status of a specific job
-func (h *JobsHandler) GetJobStatus(c echo.Context) error {
+func (h *JobsHandler) GetJobStatus(c *echo.Context) error {
 	jobID := c.Param("jobId")
 
 	result, exists := h.worker.GetJobStatus(jobID)