feat: bound connect attempts with a 30 s default connectionTimeout (#2320)

connectionTimeout defaulted to 0, which InspectorClient.connect() read as
"no bound at all" — so out of the box nothing the Inspector owns bounded a
connect attempt, and the only thing ending a hung handshake was the SDK's
60 s per-request timeout on initialize, reporting "Request timed out".

- Add DEFAULT_CONNECTION_TIMEOUT_MS (30000) to core/mcp/types.ts. An absent
  value resolves to it on the client, on disk read, in the web form draft,
  and in the CLI's header-only settings shell. An explicit 0 keeps its
  documented meaning (no timeout; --connect-timeout 0) and is now persisted
  so the opt-out round-trips; the default is the omit-sentinel, as for
  taskTtl.
- Key the post-timeout transport teardown to the timer actually firing, not
  to connectionTimeout > 0 — otherwise a non-zero default would tear down
  every failed connect, including a recoverable 401 whose transport the
  auth recovery holds open.
- The timeout message names the bound and where to raise it: "Connection
  timed out after N ms. To accommodate a slower server, you may increase
  the timeout value in Server Settings."
- The CLI's UNREACHABLE classifier now matches that message.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M4h8Xa6Ed9zwtv5ojX35MT
Signed-off-by: cliffhall <cliff@futurescale.com>

core/mcp/node/servers.ts

@@ -1,7 +1,11 @@
 import type { SecretStore } from "../../auth/node/secret-store.js";
 import { defaultSecretStore } from "../../auth/node/secret-store-selection.js";
 import type { InspectorServerSettings, MCPServerConfig } from "../types.js";
-import { DEFAULT_MAX_FETCH_REQUESTS, DEFAULT_TASK_TTL_MS } from "../types.js";
+import {
+  DEFAULT_CONNECTION_TIMEOUT_MS,
+  DEFAULT_MAX_FETCH_REQUESTS,
+  DEFAULT_TASK_TTL_MS,
+} from "../types.js";
 import { mcpConfigToServerEntries } from "../serverList.js";
 import {
   applyOverrides,
@@ -50,7 +54,7 @@ export function headersToServerSettings(
     headers: Object.entries(headers).map(([key, value]) => ({ key, value })),
     env: [],
     metadata: {},
-    connectionTimeout: 0,
+    connectionTimeout: DEFAULT_CONNECTION_TIMEOUT_MS,
     requestTimeout: 0,
     taskTtl: DEFAULT_TASK_TTL_MS,
     maxFetchRequests: DEFAULT_MAX_FETCH_REQUESTS,