fix(#2852): forward model overrides from categories/agent config to subagents

- fix(switcher): use lastIndexOf for multi-slash model IDs (e.g. aws/anthropic/claude-sonnet-4)
- fix(model-resolution): same lastIndexOf fix in doctor parseProviderModel
- fix(call-omo-agent): resolve model from agent config and forward to both
  background and sync executors via DelegatedModelConfig
- fix(subagent-resolver): inherit category model/variant when agent uses
  category reference without explicit model override
- test: add model override forwarding tests for call-omo-agent
- test: add multi-slash model ID test for switcher

src/hooks/preemptive-compaction.test.ts

@@ -451,7 +451,9 @@ describe("preemptive-compaction", () => {
 
     expect(ctx.client.session.summarize).toHaveBeenCalledTimes(1)
 
-    // when - new message with high tokens (context grew after compaction)
+    // when - advance past the 60s cooldown window, then new message with high tokens
+    const originalNow = Date.now
+    Date.now = () => originalNow() + 61_000
     await hook.event({
       event: {
         type: "message.updated",
@@ -480,6 +482,7 @@ describe("preemptive-compaction", () => {
 
     // then - summarize should fire again
     expect(ctx.client.session.summarize).toHaveBeenCalledTimes(2)
+    Date.now = originalNow
   })
 
   // #given modelContextLimitsCache has model-specific limit (256k)