Temporal Timeout Configuration Standards

This rule applies to files matching the patterns above.

# Temporal Timeout Configuration Standards

## Rule
Every workflow and activity MUST have explicit timeout configuration. Never rely on defaults for production workloads.

## Format
```typescript
proxyActivities({
  startToCloseTimeout: "required",
  heartbeatTimeout: "required for long-running",
  scheduleToCloseTimeout: "optional but recommended",
});
```

## Requirements

### 1. Activity Timeouts
```typescript
// startToCloseTimeout: Max time for a single activity attempt
// scheduleToCloseTimeout: Max total time including retries
// heartbeatTimeout: Max time between heartbeats (detect stuck activities)

const { quickActivity } = proxyActivities({
  startToCloseTimeout: "30s",     // Quick API call
});

const { longActivity } = proxyActivities({
  startToCloseTimeout: "10m",     // File processing
  heartbeatTimeout: "30s",         // Must heartbeat every 30s
  scheduleToCloseTimeout: "1h",   // Total including retries
});

const { externalApiCall } = proxyActivities({
  startToCloseTimeout: "5s",      // Fast timeout for APIs
  retry: {
    maximumAttempts: 3,
    initialInterval: "1s",
  },
  scheduleToCloseTimeout: "30s",  // Total budget for all retries
});
```

### 2. Workflow Execution Timeout
```typescript
// Set at workflow start — prevents zombie workflows
await client.workflow.start(orderFulfillmentWorkflow, {
  workflowId: "order-123",
  taskQueue: "orders",
  workflowExecutionTimeout: "7d",  // Max workflow lifetime
  workflowRunTimeout: "24h",       // Max single run (before ContinueAsNew)
  args: [order],
});
```

### 3. Timeout Guidelines by Activity Type
```
Activity Type           startToClose   heartbeat    scheduleToClose
API call (fast)         5-10s          -            30s
API call (slow)         30-60s         -            5m
Database query          10-30s         -            2m
File processing         5-30m          30s          2h
Email/notification      10s            -            1m
External webhook        30s            -            5m
Data migration          1-4h           60s          8h
```

### 4. ContinueAsNew for Long-Running Workflows
```typescript
import { continueAsNew } from "@temporalio/workflow";

export async function longRunningWorkflow(state: WorkflowState): Promise<void> {
  // Process events until history gets large
  while (state.eventsProcessed < state.totalEvents) {
    await processNextBatch(state);
    state.eventsProcessed += 100;

    // Prevent history from growing too large (> 50K events)
    if (state.eventsProcessed % 10000 === 0) {
      await continueAsNew<typeof longRunningWorkflow>(state);
    }
  }
}
```

## Anti-Patterns
- No timeout on activities (run indefinitely if stuck)
- No workflow execution timeout (zombie workflows accumulate)
- Heartbeat timeout longer than startToClose (useless)
- Too-short timeouts causing unnecessary retries (wasted resources)
- Not using ContinueAsNew for workflows with large histories

## Enforcement
Require timeout configuration in code review for all activity proxy declarations. Alert on workflows exceeding 50K history events.