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/conflicts.go

@@ -11,7 +11,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgtype"
-	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v5"
 )
 
 type ConflictHandler struct {
@@ -64,7 +64,7 @@ type ConflictResolveResponse struct {
 	DevicesSynced    []string        `json:"devices_synced"`
 }
 
-func (h *ConflictHandler) GetConflictsData(c echo.Context) ([]ConflictDetailResponse, int, int, error) {
+func (h *ConflictHandler) GetConflictsData(c *echo.Context) ([]ConflictDetailResponse, int, int, error) {
 	user := c.Get("user").(database.Users)
 
 	status := c.QueryParam("status")
@@ -126,7 +126,7 @@ func (h *ConflictHandler) GetConflictsData(c echo.Context) ([]ConflictDetailResp
 	return response, len(response), unresolvedCount, nil
 }
 
-func (h *ConflictHandler) ListConflicts(c echo.Context) error {
+func (h *ConflictHandler) ListConflicts(c *echo.Context) error {
 	conflicts, total, unresolved, err := h.GetConflictsData(c)
 	if err != nil {
 		return echo.NewHTTPError(http.StatusInternalServerError, "failed to list conflicts")
@@ -139,7 +139,7 @@ func (h *ConflictHandler) ListConflicts(c echo.Context) error {
 	})
 }
 
-func (h *ConflictHandler) GetConflict(c echo.Context) error {
+func (h *ConflictHandler) GetConflict(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	conflictID, err := uuid.Parse(c.Param("id"))
@@ -194,7 +194,7 @@ func (h *ConflictHandler) GetConflict(c echo.Context) error {
 	return c.JSON(http.StatusOK, detail)
 }
 
-func (h *ConflictHandler) ResolveConflict(c echo.Context) error {
+func (h *ConflictHandler) ResolveConflict(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	conflictID, err := uuid.Parse(c.Param("id"))
@@ -365,7 +365,7 @@ func (h *ConflictHandler) notifyDevicesOfResolution(mediaItemID pgtype.UUID, dat
 	return synced
 }
 
-func (h *ConflictHandler) DeleteConflict(c echo.Context) error {
+func (h *ConflictHandler) DeleteConflict(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	conflictID, err := uuid.Parse(c.Param("id"))
@@ -393,7 +393,7 @@ func (h *ConflictHandler) DeleteConflict(c echo.Context) error {
 	return c.NoContent(http.StatusNoContent)
 }
 
-func (h *ConflictHandler) DismissAllResolved(c echo.Context) error {
+func (h *ConflictHandler) DismissAllResolved(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	conflicts, err := h.db.ListSyncConflictsByUser(context.Background(), user.ID)
@@ -435,7 +435,7 @@ type ConflictResult struct {
 	Winner     string `json:"winner,omitempty"`
 }
 
-func (h *ConflictHandler) BulkResolveConflicts(c echo.Context) error {
+func (h *ConflictHandler) BulkResolveConflicts(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	var req BulkResolveRequest
@@ -694,7 +694,7 @@ func (h *ConflictHandler) applyResolution(mediaItemID pgtype.UUID, userID pgtype
 	return err
 }
 
-func (h *ConflictHandler) BulkDismissConflicts(c echo.Context) error {
+func (h *ConflictHandler) BulkDismissConflicts(c *echo.Context) error {
 	user := c.Get("user").(database.Users)
 
 	var req struct {