fix(proxy): tell a request the server started from a result

[Cedric921]

Closes #7.

What this changes

replyFor looked an incoming server message up in listRequestIds and openCalls by id alone. Client and server number their ids independently, so a request the server starts can carry the id of a call the client has open. On main, with tools/call id 1 open, {"id":1,"method":"sampling/createMessage"} arriving from the server:

• retires the open call and writes a ledger row with an empty result
• runs the server's own request through frameResult and withNotes, so it reaches the client rewritten
• lets the real result through afterwards, unrecorded and unframed
• and where the id belonged to an open tools/list, fires onListing([]) and wipes the manifest

One condition fixes it: a server message counts as a response only when it has no method and does carry a result or an error. Anything the server started — request or notification — goes to the client untouched.

How it was verified

Seven tests, all of which fail on main:

• sampling/createMessage, roots/list, elicitation/create and ping each reach the client with their method intact, and no row is written for a call that has not come back
• the real result that follows is still recorded and still framed — the test puts instruction-shaped text in it and asserts the quotation marker, so the collision cannot silently cost the framing
• an open tools/list keeps its manifest when a roots/list steals its id, and still reads the listing when the real response arrives
• a server notification, which carries no id at all, passes through

Test Files  286 passed (286)
     Tests  8460 passed (8460)

prettier, tsc, vitest and knip all clean, on Node 24.

Checklist

• pnpm format && pnpm typecheck && pnpm test && pnpm deadcode all pass
• Behaviour change ships with a test
• No any, no magic values, no console.* outside cli-output.ts
• If this touches the decision path: still deterministic — one shape check on a message, no model, network or randomness
• If this changes a verb table: n/a
• If this changes a command, flag or file it writes: n/a; the ledger stops gaining rows for calls that have not returned, which the changeset names