Fix: Resolve parsing error and svelte/no-at-html-tags linting issues

Resolved a critical parsing error in leads_view_lead.svelte due to incorrect Svelte class directive syntax.

Addressed multiple svelte/no-at-html-tags linting errors across the following files to mitigate potential XSS vulnerabilities and improve code safety:
- src/routes/events_leads/exhibit/[slug]/leads_add_scan.svelte
- src/routes/events_leads/exhibit/[slug]/leads_manage.svelte
- src/routes/events_leads/exhibit/[slug]/leads_view_lead.svelte

Replaced {@html} blocks with safer Svelte conditional rendering ({#if}) and direct interpolation ({value}) for static and dynamic content where appropriate. Removed commented-out {@html} tags that were still triggering linting errors.

package.json

@@ -19,7 +19,6 @@
 		"test:unit": "vitest"
 	},
 	"devDependencies": {
-		"@eslint/eslintrc": "^3.3.1",
 		"@eslint/js": "^9.39.1",
 		"@playwright/test": "^1.28.1",
 		"@skeletonlabs/skeleton": "^3.1.3",
@@ -124,6 +123,7 @@
 		"openai": "^5.20.1",
 		"qrcode": "^1.5.4",
 		"shadcn-svelte": "^1.0.0",
-		"svelte-persisted-store": "^0.12.0"
+		"svelte-persisted-store": "^0.12.0",
+		"typescript-eslint": "^8.47.0"
 	}
 }