Equation support in Explore Logs

### Problem Statement

**Feature Request:**
Customers doing advanced analytics on logs and telemetry need richer scalar math + statistical functions inside queries and alert conditions.

This is a feature gap compared to other tools that support functions such as max_of, percentile, bin, etc.

**Requirement:**
Compare different columns in the same row or perform more complex arithmetic / scalar functions.

**Example:**
Alert on “Worst Case” Latency

**Goal:**
Track two latency-related duration values (staticThreshold, dynamicThreshold) and alert on whichever is higher.

**Example KQL Query:**
```
requests
| project id, staticThreshold, dynamicThreshold
| extend worst_case_duration = max_of(staticThreshold, dynamicThreshold)
| where worst_case_duration > 1000
```

Sentry does not support scalar functions like max_of(), so users must alert on both values independently, which creates duplicate alerts and unnecessary noise.

**Additional Expectations / Requested Functions:**
Users expect access to a library of scalar/statistical functions including:
max_of(a, b)
min_of(a, b)
percentile(...)
bin(...)
stddev(...)
potentially other common math / stats helpers

### Solution Brainstorm

_No response_

### Product Area

Explore