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>

harness/tools/plan_submit.json

@@ -1,6 +1,6 @@
 {
   "name": "plan_submit",
-  "scope": "cli",
+  "scope": "shared",
   "risk": "interact",
   "exclusive": true,
   "block": "tool",
@@ -11,17 +11,14 @@
     ],
     "llembas": []
   },
-  "description": "Present your finished plan for approval — only in plan mode, and only once the plan file is written.\n\n- `path`: the plan file you wrote under the plans directory.\n- The user approves it (and you continue, now allowed to make the changes), asks for a revision (change the file, then call plan_submit again), or asks you a question (answer it, then call plan_submit again).",
+  "description": "Present the plan written with plan_write for approval — only in plan mode, and only once the plan is written.\n\n- The user approves it (and you continue, now allowed to make the changes), asks for a revision (change the plan with plan_write or plan_update, then call plan_submit again), or asks you a question (answer it, then call plan_submit again).",
   "parameters": {
     "type": "object",
     "properties": {
       "path": {
         "type": "string",
-        "description": "The plan file"
+        "description": "Ignored: the plan is the one written with plan_write. Kept for callers that still send it."
       }
-    },
-    "required": [
-      "path"
-    ]
+    }
   }
 }