Add per-model generation settings to the model selector

Each text and vision harness setting now carries the generation settings
its model takes (temperature, sampling limits, penalties, seed, reasoning
effort), edited in a modal under the model pick so the harness block stays
short. Nothing is set by default, so models keep their provider's own
values until a super admin or admin changes them.

A setting is only offered and only sent when the catalog says the model
takes it: OpenRouter's supported_parameters is now stored on
harness_models and refreshed by the hourly sync. Other providers list no
parameters, so their models get them all.

db/schema.ts

@@ -1563,6 +1563,12 @@ const schema: BUN_SQLITE_DatabaseSchemaType = {
                     dataType: "TEXT",
                     json: true,
                 },
+                {
+                    fieldName: "supported_parameters",
+                    fieldDescription: `JSON array of the request fields the model takes (OpenRouter's supported_parameters), so only the generation settings it honors are offered`,
+                    dataType: "TEXT",
+                    json: true,
+                },
                 {
                     fieldName: "intelligence_score",
                     fieldDescription: `Artificial Analysis intelligence index`,