Move shape_handle into Logger metadata for No-consumer error

.changeset/fix-no-consumer-log-shape-handle.md

@@ -0,0 +1,5 @@
+---
+'@core/sync-service': patch
+---
+
+Emit `shape_handle` as Logger metadata (instead of interpolating it into the message body) for the "No consumer process when waiting on initial snapshot creation" error. This keeps the message text static so Sentry can deduplicate these events properly during incidents.

packages/sync-service/lib/electric/shape_cache.ex

@@ -189,7 +189,8 @@ defmodule Electric.ShapeCache do
                     ])
 
                     Logger.error(
-                      "No consumer process when waiting on initial snapshot creation for #{shape_handle}"
+                      "No consumer process when waiting on initial snapshot creation",
+                      shape_handle: shape_handle
                     )
 
                     {:error, :unknown}

packages/sync-service/test/electric/shape_cache_test.exs

@@ -1070,7 +1070,7 @@ defmodule Electric.ShapeCacheTest do
 
       assert String.contains?(
                log,
-               "[error] No consumer process when waiting on initial snapshot creation for #{shape_handle}"
+               "shape_handle=#{shape_handle} [error] No consumer process when waiting on initial snapshot creation"
              )
 
       assert_receive {ShapeCache.ShapeCleaner, :cleanup, ^shape_handle}