Hook `ask` decisions show raw JSON instead of diff view

Describe the bug

Copilot CLI normally shows a rich diff/content view when asking permission to create or edit a file. However, when the ask decision comes from a PreToolUse hook (i.e. the hook returns {"permissionDecision": "ask", "permissionDecisionReason": "..."}) rather than from the default built-in ask-before-write behavior, that rich diff view does not get triggered.

Instead, the "Hook permission request" dialog renders the permissionDecisionReason correctly as readable yellow text, but shows the proposed change as a single JSON line containing the raw tool input (file path plus the entire file content field), hard-wrapped at the current terminal width. For a file write/edit with non-trivial content this becomes a wall of wrapped JSON (quotes, escaped \n, braces, etc.) that is effectively unreadable, instead of the normal diff view Copilot CLI already has and uses elsewhere.

Affected version

$ copilot --version
GitHub Copilot CLI 1.0.70.

Steps to reproduce the behavior

1. Configure a PreToolUse hook script for Copilot CLI (a hook that reads the tool-call JSON from stdin and can return a permission decision).
2. Have the hook return an ask decision for a file create/edit tool call, e.g.:

   {
     "permissionDecision": "ask",
     "permissionDecisionReason": "Human review requested for this file write."
   }
   

3. Trigger a tool call that creates or edits a file with non-trivial (multi-line) content.
4. Observe the "Hook permission request" dialog that Copilot CLI shows: compare it to the normal ask-before-write dialog (without a hook forcing ask), which renders a proper diff/content view for the same kind of file change.

Expected behavior

• The permissionDecisionReason should display as it currently does (readable yellow text) — this part works correctly.
• When the ask decision is produced by a hook for a file create/edit tool, the dialog should render the proposed change using the same rich diff/content view Copilot CLI already uses for its default ask-before-write flow, instead of falling back to a single wrapped line of raw JSON tool input.

Additional context

• OS: Windows 11
• CPU architecture: x86_64
• Terminal: Windows Terminal
• Shell: PowerShell 7 — note that Copilot CLI runs its own tool calls (including file create/edit) via its internal PowerShell invocation regardless of the interactive shell, so this shouldn't affect reproduction

Riproduci il problema tramite un hook PreToolUse che restituisca una decisione ask per la creazione o la modifica di un file multilinea, quindi confronta la finestra di dialogo Hook permission request con il flusso ask-before-write predefinito. Traccia il punto di ingresso di hook permission request e la diff/content view esistente; il lavoro è completato quando il percorso dell’hook conserva il motivo leggibile e utilizza la stessa vista avanzata invece di JSON grezzo con ritorno a capo.