M0.9: commands refuse parameter names they don't take (#1413)

A misspelt parameter name was ignored and the command reported success,
answering as if the parameter hadn't been given (`comment.list
{"filterr": "open"}` listed resolved threads). `Session::execute` now
refuses names the command's params doc doesn't list, naming them and
what the command takes, before the command runs, so every path into a
command (CLI, batches, control channel, MCP, plugins, the UI) gets the
check.

The names come from the existing docs, parsed once with the registry:
each top-level item's first word and the words joined to it by `|`, `/`
or `+`, bracketed text and what follows `:`, `=` or `→` being
description, alternative groups (`{x, y} | {points}`) included. `ids`
and `id` are always taken (`params::targets` reads either); node.set,
whose doc is its props list, keeps its own check.

The junk sweep runs each junk object as given and cut down to the names
a command takes, so the junk values still reach the parsers. Tests that
passed names their command never read (comment.resolve's author,
collab.host's link, node.get's depth) pass only what it takes.

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

crates/engine/src/session/exec.rs

@@ -18,6 +18,7 @@ impl Session {
     /// as it was.
     pub fn execute(&mut self, id: &str, params: &Value) -> Result<Value> {
         let spec = find_command(id).ok_or_else(|| EngineError::UnknownCommand(id.to_string()))?;
+        crate::cmd::refuse_unknown_params(id, params)?;
         board::refuse_on_board(self, id)?;
         // Revert replaces the document's uid: refuse before ending previews or syncing branches.
         if id == "file.revert" && self.live().doc_uid.is_some() {