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/provider/openai-chat.ts

@@ -63,14 +63,19 @@ export function toOpenAIMessages(system: string, messages: Message[], vision: bo
 /** Reassembles streamed tool-call fragments, keyed by index (the only field on every fragment). */
 export class ToolCallAccumulator {
   private calls = new Map<number, { id: string; name: string; args: string }>()
+  /** The index of the call started last: a delta without one continues it (quirks.json
+   *  tool-call-without-index; conformance toolcall_index.json). */
+  private last = 0
 
   feed(fragments: unknown): { index: number; name?: string; argsDelta: string }[] {
     const deltas: { index: number; name?: string; argsDelta: string }[] = []
     if (!Array.isArray(fragments)) return deltas
     for (const f of fragments as any[]) {
       if (!f || typeof f !== "object") continue
-      // Some servers omit index when there is only one call.
-      const index = Number.isInteger(f.index) ? (f.index as number) : 0
+      // Some servers omit the index: the fragment belongs to the call started last, and the
+      // first fragment of a stream without one starts call 0.
+      const index = Number.isInteger(f.index) ? (f.index as number) : this.last
+      this.last = index
       let call = this.calls.get(index)
       if (!call) this.calls.set(index, (call = { id: "", name: "", args: "" }))
       if (f.id) call.id = String(f.id)