Implement jsxSideEffects option for JSX dead code elimination control (#22298)

## Summary
Implements the `jsxSideEffects` option to control whether JSX elements
are marked as pure for dead code elimination, matching esbuild's
behavior from their TestJSXSideEffects test case.

## Features Added
- **tsconfig.json support**: `{"compilerOptions": {"jsxSideEffects":
true}}`
- **CLI flag support**: `--jsx-side-effects`
- **Dual runtime support**: Works with both classic
(`React.createElement`) and automatic (`jsx`/`jsxs`) JSX runtimes
- **Production/Development modes**: Works in both production and
development environments
- **Backward compatible**: Default value is `false` (maintains existing
behavior)

## Behavior
- **Default (`jsxSideEffects: false`)**: JSX elements marked with `/*
@__PURE__ */` comments (can be eliminated by bundlers)
- **When `jsxSideEffects: true`**: JSX elements NOT marked as pure
(always preserved)

## Example Usage

### tsconfig.json
```json
{
  "compilerOptions": {
    "jsxSideEffects": true
  }
}
```

### CLI
```bash
bun build --jsx-side-effects
```

### Output Comparison
```javascript
// Input: console.log(<div>test</div>);

// Default (jsxSideEffects: false):
console.log(/* @__PURE__ */ React.createElement("div", null, "test"));

// With jsxSideEffects: true:
console.log(React.createElement("div", null, "test"));
```

## Implementation Details
- Added `side_effects: bool = false` field to `JSX.Pragma` struct
- Updated tsconfig.json parser to handle `jsxSideEffects` option  
- Added CLI argument parsing for `--jsx-side-effects` flag
- Modified JSX element visiting logic to respect the `side_effects`
setting
- Updated API schema with proper encode/decode support
- Enhanced test framework to support the new JSX option

## Comprehensive Test Coverage (12 Tests)
### Core Functionality (4 tests)
- ✅ Classic JSX runtime with default behavior (includes `/* @__PURE__
*/`)
- ✅ Classic JSX runtime with `side_effects: true` (no `/* @__PURE__ */`)
- ✅ Automatic JSX runtime with default behavior (includes `/* @__PURE__
*/`)
- ✅ Automatic JSX runtime with `side_effects: true` (no `/* @__PURE__
*/`)

### Production Mode (4 tests)  
- ✅ Classic JSX runtime in production with default behavior
- ✅ Classic JSX runtime in production with `side_effects: true`
- ✅ Automatic JSX runtime in production with default behavior  
- ✅ Automatic JSX runtime in production with `side_effects: true`

### tsconfig.json Integration (4 tests)
- ✅ Default tsconfig.json behavior (automatic runtime, includes `/*
@__PURE__ */`)
- ✅ tsconfig.json with `jsxSideEffects: true` (automatic runtime, no `/*
@__PURE__ */`)
- ✅ tsconfig.json with `jsx: "react"` and `jsxSideEffects: true`
(classic runtime)
- ✅ tsconfig.json with `jsx: "react-jsx"` and `jsxSideEffects: true`
(automatic runtime)

### Snapshot Testing
All tests include inline snapshots demonstrating the exact output
differences, providing clear documentation of the expected behavior.

### Existing Compatibility
- ✅ All existing JSX tests continue to pass
- ✅ Cross-platform Zig compilation succeeds

## Closes
Fixes #22295

🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

docs/bundler/vs-esbuild.md

@@ -245,8 +245,8 @@ In Bun's CLI, simple boolean flags like `--minify` do not accept an argument. Ot
 ---
 
 - `--jsx-side-effects`
-- n/a
-- JSX is always assumed to be side-effect-free
+- `--jsx-side-effects`
+- Controls whether JSX expressions are marked as `/* @__PURE__ */` for dead code elimination. Default is `false` (JSX marked as pure).
 
 ---
 
@@ -617,7 +617,7 @@ In Bun's CLI, simple boolean flags like `--minify` do not accept an argument. Ot
 
 - `jsxSideEffects`
 - `jsxSideEffects`
-- Not supported in JS API, configure in `tsconfig.json`
+- Controls whether JSX expressions are marked as pure for dead code elimination
 
 ---