refactor(mcp): typed Rx refs for prefab Confirm args + pin no-SendMessage on Cancel

[dougborg]

Summary

Closes #54, closes #53.

#54 — Typed Rx refs for CallTool template args. The four Confirm-button CallTool actions used bare-string templates like "{{ preview.order_id }}" to bind iframe state into tool arguments. A typo ("{{ preivew.order_id }}") would silently expand to empty and the host would call the tool with a missing arg — opaque failure. Added a _preview_ref(field) -> Rx helper; the four builders now route through it:

arguments={
    "order_id": _preview_ref("order_id"),
    "status_code": _preview_ref("new_status_code"),
    ...
},

Wire shape is identical (Rx serializes to the same template string), so all 16 existing tests continue to pass. The win is a single namespaced choke-point: the preview. prefix can no longer be typo'd, and field names are greppable.

#53 — Pin no-SendMessage on Cancel. PR #83 already replaced the old SendMessage("Cancel the X") chain with [SetState("cancelled", True), ShowToast(...)], but no test enforced that contract. Added test_cancel_buttons_do_not_send_chat_messages which walks every preview card's envelope, finds each Cancel button, and asserts no sendMessage action in the on_click chain.

Test plan

• uv run poe check — 300/300 Python tests pass (was 299, +1 new test)
• All existing prefab UI assertions on "{{ preview.X }}" still pass — Rx serializes to the same template string
• New test_cancel_buttons_do_not_send_chat_messages would fail if any builder regresses to SendMessage on Cancel
• Manual: clicking Cancel in Claude Desktop still surfaces the toast + "Cancelled" pill without a chat message

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Refactors the MCP prefab preview-card builders to use a centralized, typed Rx helper for preview.* tool-argument bindings, and adds a regression test ensuring Cancel buttons don’t reintroduce chat-noise by firing SendMessage.

Changes:

• Introduced _preview_ref(field) -> Rx and routed all 4 preview-card Confirm CallTool(arguments=...) bindings through it.
• Added test_cancel_buttons_do_not_send_chat_messages to assert Cancel buttons never include a sendMessage action in their onClick chain.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
statuspro_mcp_server/src/statuspro_mcp/tools/prefab_ui.py	Centralizes preview.* reactive argument references via _preview_ref and updates Confirm CallTool argument wiring in all preview cards.
statuspro_mcp_server/tests/tools/test_prefab_ui.py	Adds a regression test that scans preview-card envelopes to ensure Cancel buttons don’t send chat messages.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.