fix(js): Replace Unicode em dashes and arrows with ASCII

Replace em dashes (—) with hyphens (-) and arrows (→) with (->)
These Unicode characters were causing 'atob' encoding errors:
'InvalidCharacterError: Failed to execute atob on Window'

The atob function only supports Latin1 (ISO-8859-1) characters.
All special Unicode characters have been replaced with ASCII equivalents.

Author: codyde

docs/platforms/javascript/common/tracing/span-metrics/examples.mdx

@@ -22,7 +22,7 @@ Example Repository: [Crash Commerce](https://github.com/getsentry/crash-commerce
 
 **Solution:** Start a client span on the checkout action for the application, and relevant spans on the backend for each step in the checkout flow. Attach attributes that represent critical metrics for the application, such as cart size and value, and payment provider used in the transaction.
 
-**Frontend (React) — instrument the Checkout click handler:**
+**Frontend (React) - instrument the Checkout click handler:**
 
 ```javascript
 // In your Checkout button click handler
@@ -77,7 +77,7 @@ Where to put this in your app:
 - In the `onClick` for the checkout button, or inside the submit handler of your checkout form/container component.
 - Auto-instrumentation will add client `fetch` spans; keep the explicit UI span for specific application context.
 
-**Backend — Checkout API with an Order Processing span, and a Payment span:**
+**Backend - Checkout API with an Order Processing span, and a Payment span:**
 
 ```javascript
 // Example: Node/Express
@@ -160,7 +160,7 @@ app.post('/api/checkout', async (req: Request, res: Response) => {
 ```
 
 **How the trace works together:**
-- UI span starts when checkout is selected → Server Backend starts a span to continue the track when the server `/checkout` API is called. As payment processes, a payment span is started.
+- UI span starts when checkout is selected -> Server Backend starts a span to continue the track when the server `/checkout` API is called. As payment processes, a payment span is started.
 - Attributes and Span metrics let you track more than just the latency of the request. Can track store busienss performances through `cart.item_count` and other `cart` attributes, and store reliabiliyt by checking error performance on `payment.provider` properties.
 
 What to monitor with span metrics:
@@ -175,7 +175,7 @@ Example Repository: [SnapTrace](https://github.com/getsentry/snaptrace-tracing-e
 
 **Solution:** Start a client span for the entire upload experience, create a backend span for upload validation, and a separate span for async media processing. Use rich attributes instead of excessive spans to capture processing details.
 
-**Frontend (React) — Instrument Upload Action**
+**Frontend (React) - Instrument Upload Action**
 
 ```typescript
 // In your UploadForm component's upload handler
@@ -238,7 +238,7 @@ Where to put this in your app:
 - In drag-and-drop onDrop callback
 - Auto-instrumentation will capture fetch spans; the explicit span adds business context
 
-**Backend — Upload Validation and Queue Job**
+**Backend - Upload Validation and Queue Job**
 
 <Alert>
 
@@ -307,7 +307,7 @@ app.post('/api/upload', async (req: Request<{}, {}, UploadRequest>, res: Respons
 });
 ```
 
-**Backend — Async Media Processing (Consumer)**
+**Backend - Async Media Processing (Consumer)**
 
 ```typescript
 // Async media processing (runs in background via setImmediate)
@@ -412,7 +412,7 @@ Example Repository: [NullFlix](https://github.com/getsentry/nullflix-tracing-exa
 
 **Solution:** Start a client span for each debounced request, mark aborted requests, track search patterns, and on the server, instrument search performance with meaningful attributes.
 
-**Frontend (React + TypeScript) — instrument debounced search:**
+**Frontend (React + TypeScript) - instrument debounced search:**
 
 ```typescript
 const response = await Sentry.startSpan(
@@ -467,7 +467,7 @@ const response = await Sentry.startSpan(
 Where to put this in your app:
 - In your search input component, triggered after debounce timeout
 
-**Backend (Node.js + Express) — instrument search with meaningful attributes:**
+**Backend (Node.js + Express) - instrument search with meaningful attributes:**
 
 ```typescript
 app.get('/api/search', async (req: Request, res: Response) => {
@@ -528,7 +528,7 @@ app.get('/api/search', async (req: Request, res: Response) => {
 ```
 
 **How the trace works together:**
-- Client span starts when debounced search triggers → tracks the full user-perceived latency.
+- Client span starts when debounced search triggers -> tracks the full user-perceived latency.
 - Aborted requests are marked with `ui.aborted=true` and short duration, showing wasted work.
 - Server span shows search performance characteristics: mode (prefix vs fuzzy), results count, and slow queries.
 
@@ -558,7 +558,7 @@ This example follows Sentry's AI Agents Module conventions. For detailed specifi
 
 ![Custom LLM Monitoring](./img/custom-llm-monitoring.png)
 
-**Frontend (React) — Instrument AI Chat Interface:**
+**Frontend (React) - Instrument AI Chat Interface:**
 
 ```typescript
 import { useState, useEffect } from 'react';
@@ -652,7 +652,7 @@ Where to put this in your app:
 
 **Important:** Generate `sessionId` in `useEffect` to avoid hydration errors when using Server-Side Rendering (SSR). Using `Date.now()` or random values during component initialization will cause mismatches between server and client renders.
 
-**Backend — Custom LLM Integration with Tool Calls:**
+**Backend - Custom LLM Integration with Tool Calls:**
 
 ```typescript
 import { SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN } from '@sentry/core';