v0.9.0: readm3.com/paste

Pastes get a front door at https://readm3.com/paste: paste text or drop or choose a file, pick a name and expiry, get the link with Copy, Open, Raw and a ready curl line; open any paste by its link or token; CLI, curl, API and MCP examples on the page. A PDF or image can now be pasted (sent as base64 with its name; /raw serves the real bytes, SVG as plain text). The editor gains a Paste link button beside Share, signed in or not, and a New paste link on paste pages. Paste is in the nav, the homepage and the docs. PR #14.