proxy: implement setParamsByID filter (#535)

Add setParamsByID filter that applies different request parameters based
on the requested model ID, enabling per-alias behaviour for a single
loaded model.

- add SetParamsByID field to Filters struct and SanitizedSetParamsByID
method
- substitute ${MODEL_ID} and other macros in setParamsByID keys and
values
- validate no unknown macros remain in keys or values after substitution
- apply setParamsByID in proxyInferenceHandler after setParams (can
override it)
- update config-schema.json with setParamsByID definition
- update UI to show aliases and make them selectable in the Playground

closes #534

ui-svelte/src/components/ModelsPanel.svelte

@@ -165,6 +165,9 @@
               {#if model.description}
                 <p class={model.unlisted ? "text-opacity-70" : ""}><em>{model.description}</em></p>
               {/if}
+              {#if model.aliases && model.aliases.length > 0}
+                <p class="text-xs text-txtsecondary">Aliases: {model.aliases.join(", ")}</p>
+              {/if}
             </td>
             <td class="w-12">
               {#if model.state === "stopped"}

ui-svelte/src/components/playground/ModelSelector.svelte

@@ -25,6 +25,11 @@
       <optgroup label="Local">
         {#each grouped.local as model (model.id)}
           <option value={model.id}>{model.id}</option>
+          {#if model.aliases}
+            {#each model.aliases as alias (alias)}
+              <option value={alias}>  ↳ {alias}</option>
+            {/each}
+          {/if}
         {/each}
       </optgroup>
     {/if}

ui-svelte/src/lib/types.ts

@@ -9,6 +9,7 @@ export interface Model {
   description: string;
   unlisted: boolean;
   peerID: string;
+  aliases?: string[];
 }
 
 export interface Metrics {