Open an aindrive drive as a read-only folder in Memona

The plugin reaches a drive through aindrive's remote MCP endpoint with
the drive's access token. Opening a connection asks which tools the
token may call, so it works while the drive's machine sleeps. Listing,
stat and reading map to list_files, stat and read_file; a read is
statted first, and a file whose length changed in between is refused as
a conflict. Reads decode only the window asked for, straight from the
reply pieces, so any 1 MiB slice of a file up to aindrive's 8 MiB limit
fits Memona's per-call fuel.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -2,5 +2,68 @@
 
 Opens an [aindrive](https://github.com/ainetwork-ai/aindrive) drive as a
 folder inside Memona, so agents and the file manager work in it like any local
-directory, from any machine. It reaches the drive through aindrive's remote MCP
-endpoint with the drive's access token.
+directory, from any machine. The plugin is a WASI component: it speaks no
+sockets of its own and makes every request through the host's HTTP interface,
+to the drive's remote MCP endpoint, with the drive's access token.
+
+It registers one provider, `aindrive`, for the `aindrive` scheme.
+
+This package requires a Memona version that supports plugin manifest schema 2.
+
+## Connecting
+
+In aindrive, open the drive and choose **MCP** in its sidebar. Copy the
+**Server URL**, then under **Option B · Access token** generate a token and
+copy it; aindrive shows it only once.
+
+| Field | Meaning |
+| --- | --- |
+| Server URL | The drive's MCP server URL, for example `https://aindrive.ainetwork.ai/mcp/d/AbCdEf123456`. The drive's own page address, `…/d/AbCdEf123456`, works too, as does a self-hosted server. |
+| Access token | The `aind_pat_…` token, stored as a secret |
+
+Saving the connection checks the address and the token. It does not need the
+machine that shares the drive to be online, but its files only answer while
+that machine runs aindrive; until then they report the folder unavailable.
+
+## What works
+
+Browsing folders and reading files. aindrive reads a file whole, at most
+8 MiB at a time, so a larger file is refused as unsupported rather than cut
+short. A read is checked against the size the drive reported a moment before,
+so a file that changes in between is a conflict rather than a mix of two
+versions. Names the drive's machine allows but Memona cannot show, such as one
+containing a backslash, are left out of listings.
+
+Saving, creating folders, renaming and deleting are not supported yet, and
+neither is change polling.
+
+## Building
+
+```sh
+rustup target add wasm32-wasip2
+cargo build --locked --release --target wasm32-wasip2
+```
+
+The component lands at
+`target/wasm32-wasip2/release/memona_plugin_aindrive.wasm`.
+
+`wit/filesystem.wit` is a copy of the canonical Memona filesystem contract, and
+`src/sdk.rs` generates the guest bindings from it, so this repository builds
+without a Memona checkout. Refresh the copy from `plugin_system/sdk/wit` in the
+[Memona repository](https://git.capsulizers.com/lead/memona) when the contract
+moves, and keep `apiVersion` in `manifest.json` in step.
+
+## Packaging for the plugin store
+
+A `.memona-plugin` package is a ZIP archive with the files at its root, never
+inside a directory:
+
+```sh
+cargo build --locked --release --target wasm32-wasip2
+cp target/wasm32-wasip2/release/memona_plugin_aindrive.wasm plugin.wasm
+zip memona-plugin-aindrive.memona-plugin \
+  manifest.json plugin.wasm README.md LICENSE
+```
+
+`manifest.json` and `plugin.wasm` are required; `README.md` becomes the guide on
+the plugin's public page and `LICENSE` is shown beside it.