feat(ssh): wave 3 — session-orchestrator computerId threading + transport-contract API types

Wave 3 of transparent SSH support (2 parallel owner-agents on disjoint packages).

- session-orchestrator: thread computerId end-to-end through the turn, mirroring
  cwd exactly — StartTurnInput/EnqueueInput/handleMessage/TurnLifecyclePayload
  gain computerId; runTurnDetached resolves effectiveComputerId via
  conversationStore.getEffectiveComputer(convId, override), persists the override,
  threads into RunTurnInput + ToolAssembly. Register a remote-degradation
  tools-filter (filterRemoteIncompatibleTools) that, when assembly.computerId is
  set (REMOTE), drops the 'lsp' tool + any '__'-namespaced MCP tool (local
  processes that can't see remote files); LOCAL (computerId undefined) is a
  passthrough — byte-identical to today. +21 tests.
- transport-contract: + computerId on ChatRequest (flows to ChatSendMessage) +
  computer endpoint API types (ComputerListResponse, ComputerResponse,
  ComputerStatusResponse, SetConversationComputerRequest,
  ConversationComputerResponse, SetWorkspaceDefaultComputerRequest,
  TestComputerResponse) — mirrors the cwd/workspace endpoint types.
- CR-1 (non-blocking, folded into wave 4): MCP filter doesn't preserve computerId
  on the returned ToolAssembly.
- cache-warming computerId threading intentionally DEFERRED (user request) —
  noted as a known performance-only limitation in tasks.md.

Verified: tsc -b EXIT 0, biome clean, 1620 vitest pass (was 1599, +21).
Refs: notes/ssh-support-plan.md (decisions §0.5/§13). No merge or push.

1 files changed, 45 insertions, 3 deletions

diff --git a/packages/session-orchestrator/src/queue.test.ts b/packages/session-orchestrator/src/queue.test.ts
index 225d1af..adf5d9a 100644
--- a/packages/session-orchestrator/src/queue.test.ts
+++ b/packages/session-orchestrator/src/queue.test.ts
@@ -72,6 +72,14 @@ function createInMemoryStore(): ConversationStore & {
 		async setCwd(conversationId, cwd) {
 			cwdData.set(conversationId, cwd);
 		},
+		async clearCwd(conversationId) {
+			cwdData.delete(conversationId);
+		},
+		async getComputerId() {
+			return null;
+		},
+		async setComputerId() {},
+		async clearComputerId() {},
 		async getReasoningEffort(conversationId) {
 			return effortData.get(conversationId) ?? null;
 		},
@@ -110,13 +118,44 @@ function createInMemoryStore(): ConversationStore & {
 			return null;
 		},
 		async ensureWorkspace(id) {
-			return { id, title: id, defaultCwd: null, createdAt: 0, lastActivityAt: 0 };
+			return {
+				id,
+				title: id,
+				defaultCwd: null,
+				defaultComputerId: null,
+				createdAt: 0,
+				lastActivityAt: 0,
+			};
 		},
 		async setWorkspaceTitle(id, title) {
-			return { id, title, defaultCwd: null, createdAt: 0, lastActivityAt: 0 };
+			return {
+				id,
+				title,
+				defaultCwd: null,
+				defaultComputerId: null,
+				createdAt: 0,
+				lastActivityAt: 0,
+			};
 		},
 		async setWorkspaceDefaultCwd(id, defaultCwd) {
-			return { id, title: id, defaultCwd, createdAt: 0, lastActivityAt: 0 };
+			return {
+				id,
+				title: id,
+				defaultCwd,
+				defaultComputerId: null,
+				createdAt: 0,
+				lastActivityAt: 0,
+			};
+		},
+		async setWorkspaceDefaultComputerId(id, defaultComputerId) {
+			return {
+				id,
+				title: id,
+				defaultCwd: null,
+				defaultComputerId,
+				createdAt: 0,
+				lastActivityAt: 0,
+			};
 		},
 		async deleteWorkspace() {
 			return { closedCount: 0 };
@@ -131,6 +170,9 @@ function createInMemoryStore(): ConversationStore & {
 		async getEffectiveCwd(conversationId) {
 			return cwdData.get(conversationId) ?? null;
 		},
+		async getEffectiveComputer() {
+			return null;
+		},
 	};
 }