docs(canvas): update Universal MCP snippet — molecule-mcp now standalone

The canvas tab snippet for the Universal MCP path was written before
this PR added the built-in register + heartbeat thread. Earlier wording
described it as "outbound-only — pair with the Claude Code or Python SDK
tab for heartbeat + inbound messages" — that's stale. molecule-mcp now
handles register + heartbeat itself; the only thing it doesn't yet do is
inbound A2A delivery.

Updated:
- externalUniversalMcpTemplate header comment + body — describes
  standalone behavior, points operators at SDK/channel only when they
  need INBOUND (not heartbeat).
- Drops the now-redundant curl-register step from the snippet — the
  binary registers itself on startup.
- Canvas modal label likewise updated.

No runtime / behavior change; pure docs polish so a copy-pasting
operator's mental model matches what the binary actually does.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

canvas/src/components/ExternalConnectModal.tsx

@@ -195,7 +195,7 @@ export function ExternalConnectModal({ info, onClose }: Props) {
             {tab === "mcp" && filledUniversalMcp && (
               <SnippetBlock
                 value={filledUniversalMcp}
-                label="Universal MCP — outbound tools for any MCP-aware runtime (Claude Code, hermes, codex). Pair with Python or Claude Code tab for heartbeat + inbound."
+                label="Universal MCP — standalone register + heartbeat + tools for any MCP-aware runtime (Claude Code, hermes, codex). Pair with Python or Claude Code tab if you need inbound A2A delivery."
                 copyKey="mcp"
                 copied={copiedKey === "mcp"}
                 onCopy={() => copy(filledUniversalMcp, "mcp")}

workspace-server/internal/handlers/external_connection.go

@@ -104,7 +104,7 @@ claude --channels plugin:molecule@Molecule-AI/molecule-mcp-claude-channel
 # pairing flow, push-mode upgrade, and v0.2 roadmap.
 `
 
-// externalUniversalMcpTemplate — runtime-agnostic outbound tool path.
+// externalUniversalMcpTemplate — runtime-agnostic standalone path.
 // Ships as the `molecule-mcp` console script in the
 // molecule-ai-workspace-runtime PyPI wheel (workspace/mcp_cli.py).
 // Any MCP-aware runtime (Claude Code, hermes, codex, third-party)
@@ -112,41 +112,38 @@ claude --channels plugin:molecule@Molecule-AI/molecule-mcp-claude-channel
 // container-bound runtimes use today: delegate_task, list_peers,
 // send_message_to_user, commit_memory, etc.
 //
-// Outbound-only: the binary doesn't heartbeat or accept inbound A2A.
-// Pair with the Claude Code channel tab (poll-based inbound) or the
-// Python SDK tab (push-mode inbound + heartbeat) to keep the workspace
-// online and surface inbound messages. The snippet calls that out
-// explicitly so an operator copy-pasting it doesn't end up with a
-// silently-offline workspace.
+// Standalone: the binary itself handles register-on-startup +
+// continuous heartbeats (daemon thread, 20s cadence). No separate
+// SDK or channel process needed to keep the workspace online. The
+// only thing it does NOT yet do is poll inbound A2A messages — for
+// runtimes that need their agent to react to canvas messages or
+// peer-initiated tasks, pair with the Claude Code channel tab
+// (poll-based inbound delivery into a Claude Code session) or the
+// Python SDK tab (push-mode inbound + heartbeat).
 //
 // Origin/WAF: handled automatically by platform_auth.auth_headers()
 // in the wheel — operator doesn't need to configure anything.
-const externalUniversalMcpTemplate = `# Universal MCP — call platform tools from any MCP-aware runtime
-# (Claude Code, hermes, codex, etc.). Outbound-only — pair with the
-# Claude Code or Python SDK tab for heartbeat + inbound messages.
+const externalUniversalMcpTemplate = `# Universal MCP — standalone register + heartbeat + outbound platform tools
+# for any MCP-aware runtime (Claude Code, hermes, codex, etc.).
+# Pair with the Claude Code or Python SDK tab if your runtime needs
+# inbound A2A delivery (canvas messages → agent conversation turns).
 
 # 1. Install the workspace runtime wheel:
 pip install molecule-ai-workspace-runtime
 
-# 2. One-shot register (pair with SDK/channel for ongoing heartbeat):
-export WORKSPACE_AUTH_TOKEN="<paste from create response>"
-curl -fsS -X POST "{{PLATFORM_URL}}/registry/register" \
-  -H "Authorization: Bearer $WORKSPACE_AUTH_TOKEN" \
-  -H "Origin: {{PLATFORM_URL}}" \
-  -H "Content-Type: application/json" \
-  -d '{"id":"{{WORKSPACE_ID}}","url":"","agent_card":{"name":"My Agent"},"delivery_mode":"poll"}'
-
-# 3. Wire molecule-mcp into your agent's MCP config. Claude Code:
+# 2. Wire molecule-mcp into your agent's MCP config. Claude Code:
 claude mcp add molecule -s user -- env \
   WORKSPACE_ID={{WORKSPACE_ID}} \
   PLATFORM_URL={{PLATFORM_URL}} \
-  MOLECULE_WORKSPACE_TOKEN="$WORKSPACE_AUTH_TOKEN" \
+  MOLECULE_WORKSPACE_TOKEN="<paste from create response>" \
   molecule-mcp
 
-# Same env-var contract works with hermes-agent, codex, or any MCP
-# stdio runtime. Tools exposed: delegate_task, delegate_task_async,
-# check_task_status, list_peers, get_workspace_info,
-# send_message_to_user, commit_memory, recall_memory.
+# molecule-mcp registers the workspace + heartbeats every 20s in a
+# daemon thread, then runs the MCP stdio loop. Same env-var contract
+# works with hermes-agent, codex, or any MCP stdio runtime. Tools
+# exposed: delegate_task, delegate_task_async, check_task_status,
+# list_peers, get_workspace_info, send_message_to_user,
+# commit_memory, recall_memory.
 #
 # Origin/WAF handling is built into the wheel — no manual headers
 # needed when calling tools through the MCP server.