feat(ui): add Button, Modal, Spinner, Toast, and Tooltip components with styles

- Implemented Button component with various props for customization.
- Created Modal component with header, content, and footer subcomponents.
- Added Spinner component for loading indicators.
- Developed Toast component for displaying notifications.
- Introduced Tooltip component for contextual hints with keyboard shortcuts.
- Added corresponding CSS modules for styling each component.
- Updated index file to export new components.
- Configured TypeScript settings for the UI package.

packages/shared/src/components/channel/LinkEmbed.module.css

@@ -0,0 +1,203 @@
+/* ── Link Embed — matches Fluxer's embed card ────────────────────────── */
+
+.embed {
+	position: relative;
+	display: inline-grid;
+	inline-size: fit-content;
+	max-inline-size: 100%;
+	max-width: 432px;
+	box-sizing: border-box;
+	border-radius: 8px;
+	background: var(--background-primary);
+	border: 1px solid var(--background-modifier-accent);
+	border-left: 4px solid var(--brand-primary);
+	margin-top: 4px;
+}
+
+.grid {
+	overflow: hidden;
+	padding: 12px 12px 14px 12px;
+	display: grid;
+	grid-template-columns: auto;
+	grid-template-rows: auto;
+}
+
+.embedContent {
+	min-width: 0;
+	display: flex;
+	flex-direction: column;
+	gap: 8px;
+}
+
+.embedContent > *:first-child {
+	margin-top: 4px;
+}
+
+/* Provider (e.g. "YouTube", "GitHub") */
+.provider {
+	font-size: 0.75rem;
+	line-height: 1rem;
+	font-weight: 500;
+	color: var(--text-tertiary);
+}
+
+/* Author row */
+.author {
+	display: flex;
+	align-items: center;
+	min-width: 0;
+}
+
+.authorIcon {
+	flex-shrink: 0;
+	margin-right: 8px;
+	width: 24px;
+	height: 24px;
+	object-fit: cover;
+	border-radius: 50%;
+}
+
+.authorName {
+	font-size: 0.875rem;
+	font-weight: 600;
+	color: var(--text-primary);
+	overflow: hidden;
+	text-overflow: ellipsis;
+	white-space: nowrap;
+}
+
+/* Title */
+.title {
+	font-size: 1rem;
+	font-weight: 600;
+	display: inline-block;
+	color: var(--text-link);
+	text-decoration: none;
+	cursor: pointer;
+	overflow: hidden;
+	text-overflow: ellipsis;
+	white-space: nowrap;
+}
+
+.title:hover {
+	text-decoration: underline;
+}
+
+/* Description */
+.description {
+	font-size: 0.875rem;
+	line-height: 1.125rem;
+	white-space: pre-line;
+	color: var(--text-primary);
+	display: -webkit-box;
+	-webkit-box-orient: vertical;
+	-webkit-line-clamp: 3;
+	overflow: hidden;
+}
+
+/* ── Media (image / video thumbnail) ─────────────────────────────────── */
+
+.mediaContainer {
+	position: relative;
+	border-radius: 4px;
+	overflow: hidden;
+	margin-top: 4px;
+	contain: paint;
+	cursor: pointer;
+}
+
+.mediaImage {
+	display: block;
+	max-width: 100%;
+	max-height: 300px;
+	width: 100%;
+	border-radius: 4px;
+	object-fit: cover;
+}
+
+/* Dark overlay for video thumbnails */
+.mediaOverlay {
+	position: absolute;
+	inset: 0;
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	background: rgba(0, 0, 0, 0.4);
+	opacity: 0;
+	transition: opacity 0.2s ease;
+	text-decoration: none;
+}
+
+.mediaContainer:hover .mediaOverlay {
+	opacity: 1;
+}
+
+.mediaControls {
+	display: flex;
+	align-items: center;
+	gap: 0.75rem;
+}
+
+.playButton,
+.openButton {
+	display: flex;
+	height: 3.5rem;
+	width: 3.5rem;
+	align-items: center;
+	justify-content: center;
+	border-radius: 50%;
+	background: rgba(0, 0, 0, 0.75);
+	cursor: pointer;
+	transition: background 200ms ease;
+	color: #fff;
+	border: none;
+	padding: 0;
+}
+
+.playButton:hover,
+.openButton:hover {
+	background: rgba(0, 0, 0, 0.85);
+}
+
+.openButton {
+	height: 2.75rem;
+	width: 2.75rem;
+}
+
+.directVideoWrapper {
+	position: relative;
+	display: inline-block;
+}
+
+.directVideo {
+	max-width: 400px;
+	max-height: 300px;
+	border-radius: 8px;
+	display: block;
+}
+
+.directPlayOverlay {
+	position: absolute;
+	inset: 0;
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	background: rgba(0, 0, 0, 0.35);
+	border: none;
+	border-radius: 8px;
+	cursor: pointer;
+	color: #fff;
+	transition: background 0.15s;
+}
+
+.directPlayOverlay:hover {
+	background: rgba(0, 0, 0, 0.5);
+}
+
+.directImage {
+	max-width: 400px;
+	max-height: 300px;
+	border-radius: 8px;
+	display: block;
+	object-fit: contain;
+}