feat(desktop): offer Claude effort levels in agent edit and create (#8059)

Claude Code agents now get a thinking-effort dropdown in the agent Edit
and Create dialogs, matching the one buzz-agent and Codex agents already
have.

## Behavior
- **Where levels come from:** Claude effort levels come from the Claude
model data for the model that will actually run after Save, resolved in
order: explicit model, then inherited default (linked definition or
global), then adapter default. Stored Claude session levels are not
used, because the stored session data does not record which model
produced them.
- **Edit:** for an agent linked to a definition, effort follows the
definition's model, which stays authoritative. Save never sends a model
for linked agents.
- **Create:** effort is offered for local agents only and is stored on
the instance. Allowed levels are recomputed on every render, so
collapsing Advanced and then switching to a model without effort (e.g.
Haiku) drops effort from the request. Non-local effort is rejected
before any create side effects.
- **Persistence:** `create_managed_agent` sets the picked effort when it
builds the record and drops stale effort env aliases. Its body runs over
any Tauri runtime, so a mock-app test drives the real create path and
reads the record back from disk. That test runs in a child process with
temp app-data and nest folders, and a test-only switch turns keychain
use off so agent keys stay inline in the temp agent file and the OS
keychain is never touched.
- **Observer store:** live session-config captures are written to the
store before the dialog refreshes; archived captures are read-only.
- **Codex:** its existing session-native effort picker is unchanged.

---------

Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Co-authored-by: Hayt <211b96e6a2b7f45fd4047988976c7bbbeeda0c15f3ae7b32eec20834b5a55118@buzz.block.builderlab.xyz>

desktop/src/testing/e2eBridge.ts

@@ -120,6 +120,8 @@ export type MockManagedAgentSeed = {
   personaId?: string | null;
   /** Harness/runtime id pin; `null` = inherit from persona (native default). */
   runtime?: string | null;
+  /** Model pinned on the instance record. */
+  model?: string | null;
   status?: RawManagedAgent["status"];
   channelNames?: string[];
   channelIds?: string[];
@@ -679,6 +681,10 @@ type E2eConfig = {
      * returning a catalog.
      */
     discoverAgentModelsError?: string;
+    /** Delay (ms) before `discover_agent_models` settles. */
+    discoverAgentModelsDelayMs?: number;
+    /** Config surface returned for every agent instead of the per-runtime mocks. */
+    agentConfigSurface?: Record<string, unknown>;
     /** ACP commands returned by the discovery IPC in mock mode. */
     acpCommands?: Array<{ command: string; binaryPath: string }>;
     // Backend provider mocks for the create-agent "Run on" section. See
@@ -2540,7 +2546,7 @@ function buildSeededManagedAgent(seed: MockManagedAgentSeed): MockManagedAgent {
     parallelism: 1,
     system_prompt: null,
     avatar_url: seed.avatarUrl ?? null,
-    model: null,
+    model: seed.model ?? null,
     env_vars: { ...(seed.envVars ?? {}) },
     status,
     pid: status === "running" ? 42000 + mockManagedAgents.length : null,
@@ -14175,6 +14181,10 @@ export function maybeInstallE2eTauriMocks() {
           supportsSwitching: false,
         };
       case "discover_agent_models": {
+        const discoverDelayMs = activeConfig?.mock?.discoverAgentModelsDelayMs;
+        if (discoverDelayMs) {
+          await new Promise((resolve) => setTimeout(resolve, discoverDelayMs));
+        }
         const discoverError = activeConfig?.mock?.discoverAgentModelsError;
         if (discoverError) {
           throw new Error(discoverError);
@@ -14280,6 +14290,8 @@ export function maybeInstallE2eTauriMocks() {
       }
       case "get_agent_config_surface": {
         const configArgs = payload as { pubkey: string };
+        const surfaceOverride = activeConfig?.mock?.agentConfigSurface;
+        if (surfaceOverride) return surfaceOverride;
         return buildMockConfigSurface(configArgs.pubkey);
       }
       case "get_runtime_file_config": {