feat: seed the MCP org example server as a remote first-run card (#2201)

Adds a third entry to `DEFAULT_SEED_CONFIG`, `example-server-default`, a
Streamable HTTP card pointing at the MCP org's own feature-reference server
(https://example-server.modelcontextprotocol.io/mcp). Until now every seeded
server was a local stdio process and every remote example in the docs was a
placeholder, so trying a remote connection meant finding or standing up a
server first.

The endpoint is protected by OAuth, but its authorization server advertises
Dynamic Client Registration and fronts a *mock* upstream IdP, so the whole
round trip completes with no account, no API key and no pre-registered client
— which is what makes it viable as a shipped default. Verified end to end
against a prod build: the card connects, negotiates MCP 2025-11-25 and lists
the reference server's tools.

The seed carries no `protocolEra`. That is not a default-by-omission: the
server answers the plain `initialize` handshake and rejects `server/discover`,
so it has no modern (SEP-2663) era to negotiate — `"auto"` would only buy a
failed probe and `"modern"` would fail the connection outright.

Docs updated alongside: the seeded-catalog block and per-client table in
`docs/mcp-server-configuration.md`, the Streamable HTTP example there (which
now leads with the live endpoint and keeps a placeholder to illustrate
`headers`), and the seed description in `clients/launcher/README.md`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012x3rC3JXU17aW3uSwjPoi5
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/web/src/test/core/mcp/serverList.test.ts

@@ -3,6 +3,7 @@ import {
   cleanAuthorizationParams,
   cleanRoots,
   DEFAULT_SEED_CONFIG,
+  EXAMPLE_SERVER_URL,
   envPairsToRecord,
   envRecordToPairs,
   expectedSecretFields,
@@ -865,17 +866,22 @@ describe("serializeMcpConfig", () => {
 });
 
 describe("DEFAULT_SEED_CONFIG", () => {
-  it("contains the two canonical seed servers", () => {
+  it("contains the three canonical seed servers", () => {
     expect(Object.keys(DEFAULT_SEED_CONFIG.mcpServers)).toEqual([
       "filesystem-server-default",
       "everything-server-default",
+      "example-server-default",
     ]);
   });
 
-  it("uses stdio + npx for both seeds", () => {
-    for (const cfg of Object.values(DEFAULT_SEED_CONFIG.mcpServers)) {
-      expect(cfg.type).toBe("stdio");
-      if (cfg.type === "stdio") {
+  it("uses stdio + npx for both local seeds", () => {
+    for (const key of [
+      "filesystem-server-default",
+      "everything-server-default",
+    ]) {
+      const cfg = DEFAULT_SEED_CONFIG.mcpServers[key];
+      expect(cfg?.type).toBe("stdio");
+      if (cfg?.type === "stdio") {
         expect(cfg.command).toBe("npx");
       }
     }
@@ -887,6 +893,25 @@ describe("DEFAULT_SEED_CONFIG", () => {
       expect(fs.args).toContain("/tmp");
     }
   });
+
+  it("seeds the MCP org example server over streamable-http", () => {
+    const example = DEFAULT_SEED_CONFIG.mcpServers["example-server-default"];
+    expect(example?.type).toBe("streamable-http");
+    if (example?.type === "streamable-http") {
+      expect(example.url).toBe(EXAMPLE_SERVER_URL);
+      expect(example.url).toBe(
+        "https://example-server.modelcontextprotocol.io/mcp",
+      );
+    }
+  });
+
+  it("leaves the remote seed on the default protocol era", () => {
+    // Omitted rather than written as "legacy": `serverEntriesToMcpConfig`
+    // strips the field when it equals DEFAULT_PROTOCOL_ERA, so a seed that
+    // spelled it out would round-trip into a different file than it seeded.
+    const example = DEFAULT_SEED_CONFIG.mcpServers["example-server-default"];
+    expect(example).not.toHaveProperty("protocolEra");
+  });
 });
 
 describe("extractSecretsFromStored", () => {

clients/web/src/test/core/react/useServers.test.tsx

@@ -95,6 +95,7 @@ describe("useServers", () => {
     expect(ids).toEqual([
       "filesystem-server-default",
       "everything-server-default",
+      "example-server-default",
     ]);
     // Map key is used as both id and name; connection initializes disconnected
     for (const s of result.current.servers) {