feat(mcp): connect authenticated AquaPortal tools to Vocero (#1)

Vocero needs to query AquaPortal on behalf of the caller selected by the existing phone link. This adds server-owned conversations and MCP tool execution for voice and HTTP reasoning while leaving the speech pipeline unchanged.

Release notes:

- Added browser-bound conversations that keep backend credentials server-side and isolate callers.
- Connected the eight-tool AquaPortal catalog through authenticated Streamable HTTP with full input schemas and structured results.
- Added bounded multi-step tool execution with cancellation, expiry, and stale-result protection.
- Updated browser bootstrap, tool progress, reasoning headers, and conversation cleanup.
- Disabled legacy unscoped content preloads in MCP mode and documented configuration and deployment constraints.
- Preserved disabled-mode contracts and added local SDK, WebSocket, and browser regression coverage.

Reviewed-on: AquaPortal/s2s#1

vocero-api/CHANGELOG.md

@@ -7,6 +7,18 @@ the implementation at the recorded date; current operating instructions live in
 
 ## Unreleased
 
+### Added
+
+- Added optional cookie-bound Vocero conversations that keep each caller's AquaPortal
+  session on the server, with expiry, cleanup, and isolated MCP discovery and execution.
+- Added bounded MCP tool loops to HTTP reasoning and the voice relay, preserving full
+  input schemas, structured results, source references, and conversation follow-ups.
+  Cancelled turns discard late results; the voice relay suppresses internal tool text
+  and audio without changing the speech pipeline.
+- Added browser conversation bootstrap and cleanup, authenticated discovery, per-turn
+  reasoning headers, and tool progress states. MCP mode blocks failed login and skips
+  legacy unscoped content preloads; existing behavior remains available when disabled.
+
 ### Fixed
 
 - Consolidate responsive transcript layout, keep export controls visible on narrow screens,