Enforce Svelte brace and object formatting

[niemyjski]

What changed

• Added @stylistic/eslint-plugin to the Svelte ClientApp.
• Enforced curly braces, 1TBS brace style, multiline object literals, and blank lines before consecutive control-flow blocks for .svelte and .svelte.ts files.
• Formatted existing Svelte sources to satisfy the new error-level rules.
• Added targeted disables only for six Svelte {#each} expressions that Prettier must keep inline.

Verification

• npm run validate — passed
• npm run test:unit — 47 test files / 485 tests passed; 1 unrelated existing time-ago.svelte.test.ts failure remains with effect_update_depth_exceeded
• npm run build — passed before the final rebase
• Final branch is rebased onto origin/main and pushed at 315aa02162e0f259a438cb67c15b1f2e49257f8d

No Angular files were changed.

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
Exceptionless.Insulation	37%	35%	286	❌
Exceptionless.Core	75%	67%	9992	➖
Exceptionless.Web	85%	69%	7033	✔
Exceptionless.AppHost	38%	40%	139	❌
Summary	78% (23491 / 30296)	67% (11022 / 16526)	17450	✔