Move GLM 5.2 to 5.3

GLM 5.3 supersedes 5.2, so every reference to the older id follows it: the zai
preset's opus, sonnet and fable tiers, and the fable tier of `default`, which
routes to the same model through OpenRouter.

Also the hardcoded Z.AI entries in both builds' model pickers, which are the one
place a model id is not read from a preset - leaving those would have gone on
offering a superseded model from the menu while the presets used the new one.

haiku stays on glm-4.7: that is the fast/cheap tier, not a 5.x.

presets/zai.json

@@ -7,10 +7,10 @@
     "keyRef": "zai"
   },
   "models": {
-    "opus": "glm-5.2",
-    "sonnet": "glm-5.2",
+    "opus": "glm-5.3",
+    "sonnet": "glm-5.3",
     "haiku": "glm-4.7",
-    "fable": "glm-5.2"
+    "fable": "glm-5.3"
   },
   "subagentModel": "inherit",
   "gatewayModelDiscovery": false,