refactor: remove legacy reflexes backward-compat code

BREAKING CHANGE: NerveConfig no longer has 'reflexes' field.
SenseReflexConfig/ReflexConfig types removed.
Config with top-level 'reflexes' array now errors instead of migrating.
Use sense-level 'interval' and 'on' fields instead.

- Remove reflexes from NerveConfig type
- Remove legacy parsing, deprecation warning, buildReflexesFromSenses
- Simplify reflex-scheduler to only read sense-level config
- Rename senseTriggerLabelsWithFallback → senseTriggerLabels
- Delete all legacy reflexes test cases
- -639/+114 lines

Fixes #199

packages/cli/src/__tests__/e2e-harness.ts

@@ -187,7 +187,6 @@ function defaultTestConfig(withNoopWorkflow: boolean): NerveConfig {
         on: [],
       },
     },
-    reflexes: [],
     workflows: {
       echo: { concurrency: 1, overflow: "queue" as const, maxQueue: 10 },
       ...(withNoopWorkflow ? { noop: { concurrency: 1, overflow: "drop" as const } } : {}),

packages/cli/src/commands/sense.ts

@@ -6,7 +6,7 @@ import {
   type SenseInfo,
   isPlainRecord,
   parseNerveConfig,
-  senseTriggerLabelsWithFallback,
+  senseTriggerLabels,
 } from "@uncaged/nerve-core";
 import { defineCommand } from "citty";
 
@@ -69,13 +69,13 @@ export function sensesFromConfig(configPath: string): SenseInfo[] {
   }
   const result = parseNerveConfig(raw);
   if (!result.ok) return [];
-  const { senses, reflexes } = result.value;
+  const { senses } = result.value;
   return Object.entries(senses).map(([name, cfg]) => ({
     name,
     group: cfg.group,
     throttle: cfg.throttle,
     timeout: cfg.timeout,
-    triggers: senseTriggerLabelsWithFallback(name, senses, reflexes),
+    triggers: senseTriggerLabels(name, senses),
     lastSignalTimestamp: null,
   }));
 }

packages/cli/src/commands/validate.ts

@@ -30,7 +30,9 @@ export const validateCommand = defineCommand({
 
     const config = result.value;
     const senseCount = Object.keys(config.senses).length;
-    const triggerScheduleCount = config.reflexes.length;
+    const triggerScheduleCount = Object.values(config.senses).filter(
+      (s) => s.interval !== null || s.on.length > 0,
+    ).length;
     const workflowCount = Object.keys(config.workflows).length;
 
     process.stdout.write(