feat: add SSH URL validation, inline radio buttons in repo creation dialog

RepositoryCreateDialog (already unified, used everywhere):
- Add isSshUrl() helper to detect git@ and ssh:// URLs
- Require SSH key selection when URL is SSH; show error otherwise
- Inline existing/new radio buttons with smaller styling (.repo-mode-radios)

Tests:
- Update repositories-settings-tab.test.tsx to select SSH key for owner/repo mode
- Mock listSSHKeys in tests

Quality gates: tsc --noEmit pass, npm run build pass, 80/80 tests pass

apps/web/src/styles/pages/projects.css

@@ -137,3 +137,28 @@
 	display: flex;
 	justify-content: flex-start;
 }
+
+/* Inline radio buttons for repository creation mode */
+.repo-mode-radios {
+	display: flex;
+	gap: var(--space-4);
+	flex-wrap: wrap;
+	padding: var(--space-2) 0;
+}
+
+.repo-mode-label {
+	display: inline-flex;
+	align-items: center;
+	gap: var(--space-2);
+	font-size: var(--font-size-sm);
+	font-weight: 500;
+	cursor: pointer;
+	color: var(--ink);
+}
+
+.repo-mode-label input[type="radio"] {
+	width: 18px;
+	height: 18px;
+	accent-color: var(--brand);
+	margin: 0;
+}