feat: add Coder registry links to template creation and editing (#18680)

## Summary
- Add "Browse Templates" card to starter templates page
- Add "Browse Modules" button to template editor topbar
- Both link to https://registry.coder.com as requested in #18141

<img width="1248" alt="Screenshot 2025-07-01 at 9 29 26 AM"
src="https://github.com/user-attachments/assets/2295e45c-2056-41cd-a39e-48d4379295be"
/>
<img width="943" alt="Screenshot 2025-07-01 at 9 29 45 AM"
src="https://github.com/user-attachments/assets/e0652b76-43bf-4794-825d-72b4fe7c5e5f"
/>



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

---------

Co-authored-by: Claude <noreply@anthropic.com>

site/src/pages/CreateTemplateGalleryPage/CreateTemplateGalleryPageView.tsx

@@ -4,10 +4,12 @@ import CardActionArea from "@mui/material/CardActionArea";
 import CardContent from "@mui/material/CardContent";
 import Stack from "@mui/material/Stack";
 import { ErrorAlert } from "components/Alert/ErrorAlert";
+import { Button } from "components/Button/Button";
 import { ExternalImage } from "components/ExternalImage/ExternalImage";
 import { Loader } from "components/Loader/Loader";
 import { Margins } from "components/Margins/Margins";
 import { PageHeader, PageHeaderTitle } from "components/PageHeader/PageHeader";
+import { ExternalLinkIcon } from "lucide-react";
 import type { FC } from "react";
 import { Link as RouterLink } from "react-router-dom";
 import type { StarterTemplatesByTag } from "utils/starterTemplates";
@@ -23,7 +25,21 @@ export const CreateTemplateGalleryPageView: FC<
 > = ({ starterTemplatesByTag, error }) => {
 	return (
 		<Margins>
-			<PageHeader>
+			<PageHeader
+				actions={
+					<Button asChild size="sm" variant="outline">
+						<a
+							href="https://registry.coder.com"
+							target="_blank"
+							rel="noopener noreferrer"
+							className="flex items-center"
+						>
+							Browse the Coder Registry
+							<ExternalLinkIcon className="size-icon-sm ml-1" />
+						</a>
+					</Button>
+				}
+			>
 				<PageHeaderTitle>Create a Template</PageHeaderTitle>
 			</PageHeader>
 			<Stack spacing={8}>

site/src/pages/TemplateVersionEditorPage/TemplateVersionEditor.tsx

@@ -1,5 +1,4 @@
 import { type Interpolation, type Theme, useTheme } from "@emotion/react";
-import Button from "@mui/material/Button";
 import IconButton from "@mui/material/IconButton";
 import Tooltip from "@mui/material/Tooltip";
 import { getErrorDetail, getErrorMessage } from "api/errors";
@@ -12,6 +11,7 @@ import type {
 	WorkspaceResource,
 } from "api/typesGenerated";
 import { Alert } from "components/Alert/Alert";
+import { Button } from "components/Button/Button";
 import { Sidebar } from "components/FullPageLayout/Sidebar";
 import {
 	Topbar,
@@ -25,7 +25,7 @@ import { displayError } from "components/GlobalSnackbar/utils";
 import { Loader } from "components/Loader/Loader";
 import { TriangleAlertIcon } from "lucide-react";
 import { ChevronLeftIcon } from "lucide-react";
-import { PlayIcon, PlusIcon, XIcon } from "lucide-react";
+import { ExternalLinkIcon, PlayIcon, PlusIcon, XIcon } from "lucide-react";
 import { linkToTemplate, useLinks } from "modules/navigation";
 import { ProvisionerAlert } from "modules/provisioners/ProvisionerAlert";
 import { AlertVariant } from "modules/provisioners/ProvisionerAlert";
@@ -255,6 +255,20 @@ export const TemplateVersionEditor: FC<TemplateVersionEditorProps> = ({
 							paddingRight: 16,
 						}}
 					>
+						<span className="mr-2">
+							<Button asChild size="sm" variant="outline">
+								<a
+									href="https://registry.coder.com"
+									target="_blank"
+									rel="noopener noreferrer"
+									className="flex items-center"
+								>
+									Browse the Coder Registry
+									<ExternalLinkIcon className="size-icon-sm ml-1" />
+								</a>
+							</Button>
+						</span>
+
 						<TemplateVersionStatusBadge version={templateVersion} />
 
 						<div className="flex gap-1 items-center">
@@ -312,8 +326,8 @@ export const TemplateVersionEditor: FC<TemplateVersionEditorProps> = ({
 								dismissible
 								actions={
 									<Button
-										variant="text"
-										size="small"
+										variant="subtle"
+										size="sm"
 										onClick={onCreateWorkspace}
 									>
 										Create a workspace