refactor: structured command/run payload {commandId, name, args, source}

The line field is deleted (pre-release, no shim): name and args are
parseCommand's own split — name plus verbatim rawInput with its separator
whitespace — so a consumer (a projection unit folding its own command
records, a rich command card) never re-parses a line. CommandNode mirrors
the split (name/args, both null on a run-less cross-window node); the
generic card rebuilds its display line as /name + args. The connection
fixture logs the same structured payload.

packages/ui/commands/README.md

@@ -8,7 +8,7 @@ Plugin-owned human-command registry consumed by interactive UI adapters. The [pl
 
 `ctx.commands.register(definition)` registers one lowercase command name, description, optional unstructured-input hint, and abortable handler. A registered command is available to every composed command adapter; a plugin that is incompatible with a deployment does not register there. A plain-context registration is global. A command-producing plugin mounted beneath `agent.ctx` declares its own `commands` injection and creates an exact agent-scoped definition; it shadows a global definition with the same name. This child-injection shape preserves the agent scope without making the core agent loop depend on a UI service. Duplicate names within one layer fail during registration. Every disposer is the exact Cordis effect disposer, and registration or removal notifies every `commands/change` observer so live adapters can refresh discovery; observer failures are logged and cannot veto the registry mutation or starve later observers.
 
-`list(agent)` returns immutable, name-sorted descriptors after scoped shadowing. `find(agent, name)` returns the corresponding definition. `execute(agent, line, signal)` uses `parseCommand()` and runs only a known command, returning `undefined` for invalid syntax or unknown names. A resolved command's lifecycle is durably logged on the receiving agent's session as the log-only pair `command/run` (before the handler, with a minted `commandId`, the exact line, and the issuing `CommandSource`) and `command/done` (at settlement, with the outcome kind and verbatim text; a thrown or aborted handler settles as `kind: 'error'`). Admission misses log nothing. Lifecycle appends are serialized per session through `SessionStore.appendOutOfBand`, so the service requires a composed `sessions` service.
+`list(agent)` returns immutable, name-sorted descriptors after scoped shadowing. `find(agent, name)` returns the corresponding definition. `execute(agent, line, signal)` uses `parseCommand()` and runs only a known command, returning `undefined` for invalid syntax or unknown names. A resolved command's lifecycle is durably logged on the receiving agent's session as the log-only pair `command/run` (before the handler, with a minted `commandId`, the parser's structured `name`/`args` split, and the issuing `CommandSource`) and `command/done` (at settlement, with the outcome kind and verbatim text; a thrown or aborted handler settles as `kind: 'error'`). Admission misses log nothing. Lifecycle appends are serialized per session through `SessionStore.appendOutOfBand`, so the service requires a composed `sessions` service.
 
 `parseCommand()` recognizes a slash at byte zero, a lowercase name containing letters, digits, `_`, or `-`, and either end-of-input or whitespace. It returns every byte after the name as `rawInput`, including separator whitespace; consumers own their command-specific grammar and may normalize only what that grammar permits.