cladding-init

# Cladding init Use this workflow only when the user explicitly asks to initialize, adopt, or refresh Cladding. Opening a repository alone is not consent to initialize it. ## Required host workflow If the current user message itself matches `APPLY CLADDING XXXXXX`, do not call prepare or stage again. Call `clad_init` once and copy the entire user message, including the `APPLY CLADDING` prefix, into `confirmation`. 1. If a greenfield request has no project intent, ask for one short description. 2. Call `clad_prepare_init` with exactly one starting mode: - `idea` with the user's description. - `document` with a project-relative planning-document path. - `existing` for an existing codebase; include an optional adoption goal. 3. Read the returned prompt and observations. Draft the structured object required by `clad_init` using the current host model, then call `clad_stage_init` with the preparation token and that draft. Staging validates the draft and stores only ignored runtime state under `.cladding/host/`; it does not modify authored project files. 4. Show `plannedChanges`, the staged `confirmationQuestion`, and its one-time `approvalChallenge` to the user, then stop and wait for a separate reply. The original initialization request is not confirmation. 5. Only when the user's separate reply exactly matches `approvalChallenge`, call `clad_init` with the entire reply verbatim as `confirmation`—never strip the `APPLY CLADDING` prefix. Include the draft and token wh...