fix: correct relative imports after component reorganization

Fixed import paths for 43 components moved into features/ directories.
Key fixes:
- api/, types/, hooks/, state/, utils/ imports need ../../../ from features/*/
- components/ imports need ../../ from features/*/
- Cross-feature imports use relative paths (e.g., ../tool/tools-bottom-sheet)
- app-shell.tsx updated to import from features/ subdirectories

Frontend typecheck now passes except for one pre-existing error:
xterm-addon-webgl missing type declarations.

Quality gates: ruff passed on backend, py_compile passed on all backend files.

apps/web/src/components/features/tool/manifest-editor.tsx

@@ -1,10 +1,10 @@
 import { useState, useEffect, useCallback, useRef } from "react";
-import { Icon } from "./icon";
-import { extractErrorMessage } from "../utils/errors";
+import { Icon } from "../../icon";
+import { extractErrorMessage } from "../../../utils/errors";
 import {
 	compileToolDefinition,
 	type ToolDefinitionManifest,
-} from "../api/tool_definitions";
+} from "../../../api/tool_definitions";
 
 interface PackageEntry {
 	name: string;