test: fix stale expectations after gpt-5.5 model promotion

Updates test expectations across agent, cli, shared, plugin, and tools tests

to match gpt-5.5 as the new default for oracle, hephaestus, and deep agents.

Includes snapshot updates for model-fallback tests.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin-handlers/config-handler.test.ts

@@ -1557,9 +1557,7 @@ describe("disable_omo_env pass-through", () => {
     const lastCall =
       createBuiltinAgentsMock.mock.calls[createBuiltinAgentsMock.mock.calls.length - 1]
     expect(lastCall).toBeDefined()
-    const disableOmoEnv = Array.isArray(lastCall)
-      ? lastCall[lastCall.length - 1]
-      : undefined
+    const disableOmoEnv = Array.isArray(lastCall) ? lastCall[12] : undefined
     expect(disableOmoEnv).toBe(true)
   })
 
@@ -1594,9 +1592,7 @@ describe("disable_omo_env pass-through", () => {
     const lastCall =
       createBuiltinAgentsMock.mock.calls[createBuiltinAgentsMock.mock.calls.length - 1]
     expect(lastCall).toBeDefined()
-    const disableOmoEnv = Array.isArray(lastCall)
-      ? lastCall[lastCall.length - 1]
-      : undefined
+    const disableOmoEnv = Array.isArray(lastCall) ? lastCall[12] : undefined
     expect(disableOmoEnv).toBe(false)
   })
 })