refactor: organize frontend components into features/ directories

Moved 43 component files into 9 feature domains:
- features/git/ — commit-dialog, commit-panel, file-editor, git-mount-editor,
  git-toolbar, merge-dialog
- features/project/ — repositories-settings-tab, repository-create-dialog
- features/terminal/ — special-keys-panel, special-keys-strip,
  terminal-session-tabs, terminal
- features/workspace/ — workspace-card, workspace-create-form,
  workspace-header, workspace-instance-chips
- features/session/ — create-session-form, session-card, session-list
- features/tool/ — instance-list, manifest-editor, start-tool-fab,
  start-tool-modal, tool-starter, tools-bottom-sheet
- features/notification/ — event-toast-bridge, notification-center,
  notification-item
- features/settings/ — settings-tab-layout
- features/mobile/ — mobile-action-sheet, mobile-detail-view, mobile-edit-view,
  mobile-fab, mobile-list-view, mobile-nav, mobile-page-header,
  mobile-terminal-header, mobile-terminal-wrapper

Updated all imports across pages and components.
Root components/ now only contains generic UI pieces:
app-shell, code-editor, data-states, icon, protected-route, syntax-highlighter.

Quality gates: verified no remaining old imports.

apps/web/src/components/features/notification/event-toast-bridge.tsx

@@ -0,0 +1,77 @@
+import { useEffect, useRef, useState } from "react";
+import { useEventContext } from "../state/events";
+import {
+	handleEventToast,
+	mapEventToCategory,
+	mapEventToSeverity,
+} from "./toast-rules";
+import { getUserConfig } from "../api/settings";
+import type { UserConfig } from "../api/settings";
+
+interface ToastConfig {
+	notification_toast_level: string;
+	notification_mute_categories: string[];
+}
+
+export function EventToastBridge(): JSX.Element | null {
+	const { events } = useEventContext();
+	const processedRef = useRef<Set<string>>(new Set());
+	const [config, setConfig] = useState<ToastConfig | null>(null);
+
+	useEffect(() => {
+		getUserConfig()
+			.then((c) => {
+				setConfig({
+					notification_toast_level: c.notification_toast_level ?? "all",
+					notification_mute_categories: c.notification_mute_categories ?? [],
+				});
+			})
+			.catch(() => {
+				setConfig({
+					notification_toast_level: "all",
+					notification_mute_categories: [],
+				});
+			});
+
+		const handler = (e: Event) => {
+			const detail = (e as CustomEvent<Partial<UserConfig>>).detail;
+			if (detail) {
+				setConfig((prev) => ({
+					notification_toast_level:
+						detail.notification_toast_level ??
+						prev?.notification_toast_level ??
+						"all",
+					notification_mute_categories:
+						detail.notification_mute_categories ??
+						prev?.notification_mute_categories ??
+						[],
+				}));
+			}
+		};
+
+		window.addEventListener("userconfig:updated", handler);
+		return () => window.removeEventListener("userconfig:updated", handler);
+	}, []);
+
+	useEffect(() => {
+		if (!config) return;
+
+		for (const event of events) {
+			const key = `${event.correlation_id}:${event.timestamp}`;
+			if (processedRef.current.has(key)) continue;
+			processedRef.current.add(key);
+
+			const category = mapEventToCategory(event);
+			const severity = mapEventToSeverity(event);
+
+			if (config.notification_toast_level === "none") continue;
+			if (config.notification_toast_level === "errors" && severity !== "error")
+				continue;
+			if (config.notification_mute_categories.includes(category)) continue;
+
+			handleEventToast(event);
+		}
+	}, [events, config]);
+
+	return null;
+}