fix(site): rename "AI Bridge" to "AI Gateway" in paywall card (#25677)

*Disclaimer: implemented by a Coder Agent using Claude Opus 4.6*

## Summary

Renames "AI Bridge" to "AI Gateway" in the paywall card shown on the AI
Governance settings page when the feature is not entitled.

## Changes

In `PaywallAIGovernance.tsx`:
- Title: `AI Bridge` -> `AI Gateway`
- Description text: `AI Bridge provides...` / `AI Bridge requires...` ->
`AI Gateway provides...` / `AI Gateway requires...`
- Docs link label: `AI Bridge Docs` -> `AI Gateway Docs`

site/src/components/Paywall/PaywallAIGovernance.tsx

@@ -19,13 +19,13 @@ const PaywallAIGovernance = () => {
 		<Paywall>
 			<PaywallContent>
 				<PaywallHeading>
-					<PaywallTitle>AI Bridge</PaywallTitle>
+					<PaywallTitle>AI Gateway</PaywallTitle>
 					<PremiumBadge>AI Governance</PremiumBadge>
 				</PaywallHeading>
 				<PaywallDescription>
-					AI Bridge provides auditable visibility into user prompts and LLM tool
-					calls from developer tools within Coder Workspaces. AI Bridge requires
-					a Premium license with AI Governance add-on.
+					AI Gateway provides auditable visibility into user prompts and LLM
+					tool calls from developer tools within Coder Workspaces. AI Gateway
+					requires a Premium license with AI Governance add-on.
 				</PaywallDescription>
 				<PaywallDocumentationLink href={docs("/ai-coder/ai-governance")}>
 					Learn about AI Governance
@@ -49,7 +49,7 @@ const PaywallAIGovernance = () => {
 								rel="noreferrer"
 								className="text-content-link"
 							>
-								AI Bridge Docs
+								AI Gateway Docs
 							</a>
 						</span>
 					</PaywallFeature>