Add live CLI progress for long-running jobs

CLI.md

@@ -30,6 +30,8 @@ Install the launcher from the desktop app under **Settings → Data**, or run `b
 
 The JSON envelope always has the shape `{"ok": bool, "command": string, "message": string, "data": object, "progress": [string], "notices": [string]}`, which makes the CLI safe to drive from scripts and LLM agents. Errors exit with code 1 and a formatted message on stderr; unknown commands and invalid options do the same.
 
+Long-running rebuild and render commands show live progress while comparing metadata, validating generated output, and rendering pages. An interactive terminal updates one Hugging Face-style progress bar in place; redirected output receives one stable line per update. `--json` never emits interim output and includes the ordered progress history in the final envelope.
+
 With `--airplane`, `upload`, `push`, and `pull` are refused, and AI-assisted steps (language detection, translation, image enrichment) use the configured airplane endpoint. When no local endpoint is configured, the CLI prints a notice and falls back to offline heuristics where they exist — the command-line equivalent of the desktop's airplane-mode toast.
 
 ## Command reference