fix: complete refactoring integration — rename remaining snake_case API files and fix test imports

During refactoring verification found several remaining inconsistencies:

API files (kebab-case naming):
- Rename config_profiles.ts → config-profiles.ts
- Rename tool_definitions.ts → tool-definitions.ts
- Update all imports across 8 files

Missing Python __init__.py (backend package structure):
- Add utils/__init__.py
- Add services/__init__.py
- Add schemas/__init__.py
- Add services/build/__init__.py

Test file import fixes (component reorganization fallout):
- DashboardPage.test.tsx: import from ./dashboard → ./DashboardPage
- ProjectsPage.test.tsx: import from ./projects → ./ProjectsPage
- event-toast-bridge.test.tsx: fix relative paths for moved components
  (../state/events → ../../../state/events, ./toast-rules → ../../toast-rules)
- notification-center.test.tsx: fix relative path
  (../state/notifications → ../../../state/notifications)

Quality gates: tsc --noEmit (pass), build (pass), py_compile (pass)
Tests: 9/12 test files pass (3 pre-existing UI test failures unrelated to refactoring)

apps/web/src/components/features/tool/instance-list.tsx

@@ -11,7 +11,7 @@ import {
 } from "../../../api/sessions";
 import type { ToolType } from "../../../api/tool-types";
 import { CreateSessionForm } from "../session/create-session-form";
-import { listConfigProfiles, type ConfigProfile } from "../../../api/config_profiles";
+import { listConfigProfiles, type ConfigProfile } from "../../../api/config-profiles";
 import { listSSHKeys, type SSHKey } from "../../../api/ssh-keys";
 import { useEventContext } from "../../../state/events";
 

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

@@ -4,7 +4,7 @@ import { extractErrorMessage } from "../../../utils/errors";
 import {
 	compileToolDefinition,
 	type ToolDefinitionManifest,
-} from "../../../api/tool_definitions";
+} from "../../../api/tool-definitions";
 
 interface PackageEntry {
 	name: string;

apps/web/src/components/features/tool/tool-starter.tsx

@@ -3,7 +3,7 @@
 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 { 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";