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/tool-starter.tsx

@@ -1,12 +1,12 @@
 /** Unified tool starter — workspace-first, fetches real tool types and config profiles. */
 
 import { useState, useEffect, useCallback } from "react";
-import { Icon } from "./icon";
-import { listToolTypes, type ToolType } from "../api/tool-types";
-import { listConfigProfiles, type ConfigProfile } from "../api/config_profiles";
-import { listSSHKeys, type SSHKey } from "../api/ssh-keys";
-import type { Workspace } from "../types/workspace";
-import type { ToolInstance } from "../api/sessions";
+import { Icon } from "../../icon";
+import { listToolTypes, type ToolType } from "../../../api/tool-types";
+import { listConfigProfiles, type ConfigProfile } from "../../../api/config_profiles";
+import { listSSHKeys, type SSHKey } from "../../../api/ssh-keys";
+import type { Workspace } from "../../../types/workspace";
+import type { ToolInstance } from "../../../api/sessions";
 
 export interface ToolStarterProps {
 	workspace: Workspace;
@@ -114,7 +114,7 @@ export function ToolStarter({
 		setStarting(true);
 		setError(null);
 		try {
-			const { createInstance, startInstance } = await import("../api/sessions");
+			const { createInstance, startInstance } = await import("../../../api/sessions");
 			const instance = await createInstance(
 				workspace.project_id,
 				workspace.repo_id,