Harness spec 1.1.0: one plan, prototypes and the library shared; the CLI implements it

The spec: plan_write and plan_update (new, shared, offered in every mode) and
plan_submit (now shared) keep one structured plan — findings, objectives,
phases of tasks — in place of the todo list, which lives on as a former name
of plan_write. The shared system text is one text for both projects, with
variables for what differs; the mode texts, a prototypes block and a library
block are shared. acp.md: the client hands the device what only it knows
(context, library, prototypes), the plan travels as a structure (plan_state),
library calls carry the chat's scope, and a client may rewind a session.
loop.json says its numbers as numbers. Four conformance areas: plan,
prototype, library_scope, toolcall_index.

The CLI: the plan is kept per session in the store and drawn above the prompt
and on the approval card; the prompt is assembled from the spec's texts with
their variables filled; the link reads the instance's instructions,
personalization, knowledge scope and prototype offer, sends the plan as a
structure and answers rewind; library calls to the instance carry the session
as scope; a prototype written in the terminal is saved as a file and named in
the transcript; a tool-call fragment without an index continues the last call;
the default theme is Moria; dead exports and Hermes leftovers removed.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/session/commands.ts

@@ -31,7 +31,7 @@ export interface CommandInfo {
  *  the two equal). A custom command or a skill of one of these names is not a command — in the TUI
  *  the built-in wins — so it is not one here either, even where the built-in is not offered. */
 export const TUI_COMMAND_NAMES = [
-  "agents", "continue", "help", "model", "effort", "mode", "plan", "plans", "review", "changelog", "init", "release", "tasks", "decisions", "decide",
+  "agents", "continue", "help", "model", "effort", "mode", "plan", "plans", "prototype", "review", "changelog", "init", "release", "tasks", "decisions", "decide",
   "sessions", "resume", "remote", "delete", "new", "clear", "copy", "undo", "redo", "diff", "checkpoint", "checkpoints", "branch", "commit", "context",
   "compact", "memory", "skills", "skill", "personality", "voice", "speak", "mcp", "login", "logout", "settings", "usage", "kb", "theme", "skin", "terminal",
   "icons", "trust", "reload", "restart", "quit", "exit", "q",