fix(acp): include permission request context in ACP prompts

[BunsDev]

Motivation

• The ACP bridge previously sent only a generic title like Tool 'Bash' requires approval which dropped security-critical context such as the command, target path, or detailed reason, making approval dialogs misleading.
• Users must see PermissionRequest.description, PermissionRequest.details, and PermissionRequest.path (and working dir) so they can make informed decisions for dangerous tools.

Description

• Use a synthesized permission title derived from the full PermissionRequest (tool name + details/description + path) via format_permission_title and wire it into AcpPermissionHandler::request_permission and forward_pending.
• Construct an ACP ToolCallUpdate that includes an explicit textual content block containing Tool, Description, Details, Context, Target, and Working directory via build_permission_tool_call_update / format_permission_content so clients receive the actionable context before approval.
• Add small unit tests validating that Bash command paths and FileRead targets are included in the generated title and the serialized ToolCallUpdate.

Testing

• Ran cargo test --package claurst-acp permission_ and the new focused tests passed.
• Ran cargo clippy --package claurst-acp --all-targets --no-deps -- -D warnings and it completed for the claurst-acp crate with no warnings.
• Ran git diff --check (format/lint checks) with no leftover issues for the modified file.
• cargo check --workspace was attempted but blocked by a missing system dependency (alsa.pc) required by alsa-sys in this environment; this is unrelated to the ACP change.

---

Codex Task

[Copilot]

Pull request overview

This PR enhances the ACP permission-approval UX by ensuring permission prompts carry actionable, security-relevant context (tool, description/details, targets, and working directory) instead of a generic approval title.

Changes:

• Add format_permission_title to synthesize a more informative permission title from PermissionRequest.
• Send an ACP ToolCallUpdate with an explicit text content block (tool/description/details/context/target/working dir) via build_permission_tool_call_update / format_permission_content.
• Add unit tests asserting that risky Bash commands and file targets appear in the title/content serialization.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.