fix: apply the review items for #752 and #757 at merge

The launch-id check is pure, so it now runs before the context warning and the
swap confirmation: nobody agrees to evict a model only to get the 400. Also the
search-box and in-use comments, the model-plain-colon wording, and the wiki's
order of the picker's marks.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/web/public/index.html

@@ -1034,16 +1034,17 @@
         <div class="modal-body">
           <p class="form-hint" id="customModelPickHint"></p>
           <!-- Case-insensitive filter over the rendered rows (app.filterCustomModelPick):
-               a display layer only, the rows themselves are never re-rendered. Reset and
-               focused on every open, same in-memory rule as the rail's search box. -->
+               a display layer only, the rows themselves are never re-rendered. Reset on every
+               open and focused only on non-touch devices, same in-memory rule as the rail's
+               search box. -->
           <input type="search" id="customModelPickSearch" class="session-sidebar-filter-input custom-model-pick-search"
             placeholder="Search models" aria-label="Search models"
             autocomplete="off" autocapitalize="off" spellcheck="false" enterkeyhint="search"
             oninput="app.filterCustomModelPick(this.value)">
           <p class="form-hint custom-model-pick-no-matches" id="customModelPickNoMatches" role="status" hidden>No models match</p>
-          <!-- Shown only when no row carries a loaded/in-use/last-used mark AND the endpoint
-               answered that it is not llama-swap (see _openCustomModelPickModal): it says out
-               loud WHY nothing is marked, in the user's language, rather than leaving an
+          <!-- Shown only when no row carries a loaded/in-use/last-used mark AND the
+               running-status probe answered `isLlamaSwap: false` (see
+               _openCustomModelPickModal): it says out loud WHY nothing is marked, in the user's language, rather than leaving an
                alphabetical wall that looks like the question was ignored. -->
           <p class="form-hint custom-model-pick-unknown" id="customModelPickUnknown" role="status" hidden>Nothing is marked: this endpoint did not report which model it has loaded, and none of your running sessions uses one. Pick the model to launch.</p>
           <div id="customModelPickList" class="run-mode-custom-models"></div>

src/web/routes/session-routes.ts

@@ -1548,6 +1548,30 @@ export function registerSessionRoutes(
     const contextLength = resolveCustomModelContextLength(endpoint, body.modelId);
     const slotCount = endpoint.modelSlotCounts?.[body.modelId];
 
+    // A CLI whose config alone cannot select the model also gets its `model` launch param
+    // forced (pi/omp `custom/<id>`, grok's block name, and codex now carries its bare
+    // selected id too). The argv engine DROPS a token that
+    // fails its pattern rather than quoting it, which would silently launch the CLI on its
+    // own default provider again, so refuse an id the pattern cannot carry up front.
+    // The check runs on the PURE build result, before applyCustomModelInjection below:
+    // the forced launch id only comes out of that build, and writing first would mean a
+    // refused id already replaced the config dir a live codex session uses as CODEX_HOME.
+    // It also runs before the two confirmations, so nobody agrees to evict a model only
+    // to be told the id was never usable.
+    const modelSpec = entry.launch.params.model;
+    const injection = buildCustomModelInjection(entry, endpoint, body.modelId, contextLength);
+    const forcedLaunchModel = injection.kind === 'unsupported' ? undefined : injection.launchModel;
+    if (
+      forcedLaunchModel !== undefined &&
+      modelSpec?.type === 'token' &&
+      !matchesPattern(modelSpec.pattern, forcedLaunchModel)
+    ) {
+      return createErrorResponse(
+        ApiErrorCode.INVALID_INPUT,
+        `Model id ${JSON.stringify(body.modelId)} cannot be passed to ${session.mode} on its command line`
+      );
+    }
+
     // Some CLIs (today: only claude) carry enough of their own fixed system-prompt/tool-
     // schema overhead that a small enough real context guarantees a first-message failure
     // no matter what CLAUDE_CODE_MAX_CONTEXT_TOKENS says — confirmed live at ~36.4K tokens
@@ -1611,29 +1635,6 @@ export function registerSessionRoutes(
       }
     }
 
-    // A CLI whose config alone cannot select the model also gets its `model` launch param
-    // forced (pi/omp `custom/<id>`, grok's block name, and codex now carries its bare
-    // selected id too). The argv engine DROPS a token that
-    // fails its pattern rather than quoting it, which would silently launch the CLI on its
-    // own default provider again, so refuse an id the pattern cannot carry up front.
-    // The check runs on the PURE build result, before applyCustomModelInjection below:
-    // the forced launch id only comes out of that build, and writing first would mean a
-    // refused id already replaced the config dir a live codex session uses as CODEX_HOME.
-    const modelSpec = entry.launch.params.model;
-    const injection = buildCustomModelInjection(entry, endpoint, body.modelId, contextLength);
-    if (injection.kind === 'unsupported') {
-      return createErrorResponse(ApiErrorCode.OPERATION_FAILED, `${session.mode} has no known custom-model mechanism`);
-    }
-    if (
-      injection.launchModel !== undefined &&
-      modelSpec?.type === 'token' &&
-      !matchesPattern(modelSpec.pattern, injection.launchModel)
-    ) {
-      return createErrorResponse(
-        ApiErrorCode.INVALID_INPUT,
-        `Model id ${JSON.stringify(body.modelId)} cannot be passed to ${session.mode} on its command line`
-      );
-    }
     const applied = applyCustomModelInjection(
       entry,
       endpoint,