TODO: Align code behavior with wiki documentation

1) Implement `/post` or update wiki to match actual posting behavior (plain text without leading '/').
2) Decide on config filenames and token storage:
   - Code uses `~/.config/ttyverse/ttyverserc` and a keyfile.
   - Wiki references `ttyverse_rc` and `oauth_credentials`.
3) Decide whether `/timeline` with no args should default to home and whether `/again` should follow a current timeline state; update code or docs accordingly.
4) Support `/media <path> [message]` inline message, or update docs to reflect prompt-based message entry.
5) Add `/vote` range parsing (e.g., `1-3`) or remove range examples from docs.
6) Add `/unboost` and `/reblog` alias if desired, or remove from docs.
7) Decide on `/search <query> +<count>` order vs current `+<count> <query>` parsing; align docs/code.
8) Implement or remove docs for `/version`, `/about`, `/rate`, `/restart`, `/debug` (only `/versioncheck` exists now).
9) Review search scope language in wiki (instance-limited search) and adjust if needed.
10) Add `.m4a` fallback MIME mapping if `file` is unavailable, or trim media format list in docs.
11) Update posting visibility section: `/visibility` exists; docs currently say per-post control is future work.