Extract reusable hooks from large controllers (useAppController, useHomeController)

[ryuhmanov-m]

Parent issue: #21

Context

useAppController.ts and useHomeController.ts are 800+ line controllers mixing multiple concerns. Extracting focused hooks improves testability and readability.

Scope

Extract these hooks into separate files under src/features/*/hooks/:

From useHomeController (~889 lines)

• useKeyboardShortcuts — global keyboard shortcut registration and handling
• useDragDrop — sidebar drag-and-drop logic (reorder conversations, move files)

From useAppController

• useAppInit — app initialization sequence (vault check, model load, onboarding state)

Guidelines

• Each hook should have a clear input/output interface
• Keep the same behavior — this is a refactor, not a feature change
• The parent controller should import and compose the extracted hooks
• Add a brief JSDoc comment describing the hook's purpose

Files

• src/features/layout/controllers/useAppController.ts
• src/features/chat/controllers/useHomeController.ts