cd-tool

Provides directory navigation as both a /cd <path> slash command for users and a cd tool for the LLM.

Behavior

• validates the target path before changing workspaces
• requires explicit user approval before leaving the current workspace
• asks whether an untrusted target should be trusted or opened untrusted
• recreates the session in the target workspace instead of continuing with an in-place process.chdir() mutation
• when the cd tool is used, ends the current turn and restarts in the new workspace with a one-shot synthetic transition message so the model can re-evaluate the new repo before continuing

Non-existent paths and non-directory paths return clear errors. ~ expands to home as expected.