feat(lsp,cwd): LSP integration + per-conversation cwd; fix cache-warming cache bust

LSP + per-conversation CWD feature:
- new bundled `lsp` extension: hand-rolled JSON-RPC codec (framing/rpc), lazy
  one-server-per-(serverID,root), per-cwd config resolution, on-demand `lsp` tool
- `conversation-store`: getCwd/setCwd (cwdKey); `session-orchestrator` defaults a
  turn's cwd from the store
- `transport-http`: cwd + lsp status endpoints; wire types in transport-contract
- host-bin: register lsp; config wiring

Cache-warming fix (the warm read 0% on the first reheat after a message):
- warm assembled tools under a different cwd than the real turn (a reheat sends no
  cwd, and the warm service had no store fallback). The skills filter rewrites the
  cwd-sensitive `load_skill` description, so the tools block — the first bytes of
  the prompt-cache prefix — diverged and the cache missed entirely. Warm now
  resolves cwd as opts.cwd ?? conversationStore.getCwd(), mirroring handleMessage.
- capture warm sends as `provider.request` spans flagged `warm:true` (thread a
  child logger into providerOpts) so warm vs real bodies are diffable (obs §3.1).
- kernel logger: span-close now merges child-bound attrs like span-open, so a
  `warm:true` query finds the closed span (with usage/status), not just the open.

Tests: warm forwards a warm-flagged logger; warm falls back to stored cwd; logger
open/close attr consistency. Full suite green (873).

1 files changed, 46 insertions, 0 deletions

diff --git a/packages/lsp/src/framing.test.ts b/packages/lsp/src/framing.test.ts
new file mode 100644
index 0000000..7c51a16
--- /dev/null
+++ b/packages/lsp/src/framing.test.ts
@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+import { encode, FrameDecoder } from "./framing.js";
+
+describe("framing", () => {
+	it("encode/decode round-trips", () => {
+		const msg = JSON.stringify({ jsonrpc: "2.0", method: "test", params: { a: 1 } });
+		const encoded = encode(msg);
+		const decoder = new FrameDecoder();
+		const messages = decoder.decode(encoded);
+		expect(messages).toHaveLength(1);
+		expect(messages[0]).toBe(msg);
+	});
+
+	it("decoder reassembles a frame split across two chunks", () => {
+		const msg = JSON.stringify({ jsonrpc: "2.0", method: "test" });
+		const encoded = encode(msg);
+		const mid = Math.floor(encoded.length / 2);
+		const chunk1 = encoded.slice(0, mid);
+		const chunk2 = encoded.slice(mid);
+
+		const decoder = new FrameDecoder();
+		const result1 = decoder.decode(chunk1);
+		expect(result1).toHaveLength(0);
+
+		const result2 = decoder.decode(chunk2);
+		expect(result2).toHaveLength(1);
+		expect(result2[0]).toBe(msg);
+	});
+
+	it("decoder yields two messages from one chunk", () => {
+		const msg1 = JSON.stringify({ jsonrpc: "2.0", method: "a" });
+		const msg2 = JSON.stringify({ jsonrpc: "2.0", method: "b" });
+		const encoded1 = encode(msg1);
+		const encoded2 = encode(msg2);
+
+		const combined = new Uint8Array(encoded1.length + encoded2.length);
+		combined.set(encoded1);
+		combined.set(encoded2, encoded1.length);
+
+		const decoder = new FrameDecoder();
+		const messages = decoder.decode(combined);
+		expect(messages).toHaveLength(2);
+		expect(messages[0]).toBe(msg1);
+		expect(messages[1]).toBe(msg2);
+	});
+});