feat(mcp): add list_places filter, tool annotations, prompts, and bug fixes

[Ivan-Malinovski]

Summary

This PR adds a new list_places tool with assignment filtering, adds tool annotations to all MCP tools, improves tool descriptions, and fixes several pre-existing bugs discovered during testing.

This PR was motivated by the need to bring TREK's MCP implementation in line with MCP best practices — specifically adding tool annotations so LLM clients can understand read/write semantics before making tool calls.

MCP Best Practices Compliance

Tool annotations

All 35+ tools now have proper readOnlyHint, destructiveHint, idempotentHint, and openWorldHint annotations:

• Read-only tools (TOOL_ANNOTATIONS_READONLY): list_trips, list_places, get_trip_summary, list_categories, search_place, etc.
• Write tools (TOOL_ANNOTATIONS_WRITE): update_trip, update_place, update_day, update_reservation, etc.
• Delete tools (TOOL_ANNOTATIONS_DELETE): delete_trip, delete_place, delete_budget_item, etc. (destructiveHint: true)
• Create tools (TOOL_ANNOTATIONS_NON_IDEMPOTENT): create_place, create_trip, create_reservation, etc. (create = non-idempotent)

Impact: LLM clients like Perplexity can now make safer, informed decisions about tool usage without guessing or trying to reason through side effects.

MCP Prompts

3 prompts registered for structured LLM workflows:

• trip-summary — loads full trip context before planning
• packing-list — formatted packing checklist grouped by category
• budget-overview — formatted budget summary with category breakdown

Resources

All 16 resources now have explicit mimeType: 'application/json' declarations.

Capabilities

Server announces listChanged: true for resources, tools, and prompts — informing clients when the tool set changes.

New Feature

list_places tool with assignment filter

A new MCP tool for listing places filtered by whether they're scheduled on a day:

list_places(tripId, {
  assignment: 'all'       // default — all places
  assignment: 'unassigned' // orphan activities not yet on any day
  assignment: 'assigned'   // places that ARE on a day
})

End-user impact: LLMs can now discover orphan (unassigned) activities in a trip — "Which places haven't been scheduled yet?" — enabling better travel planning workflows without manual inspection.

Also available via the trek://trips/{tripId}/places resource with ?assignment=unassigned query param.

Tool Quality Improvements

Enum descriptions

All z.enum fields now have explicit .describe() annotations so LLMs see valid options without guessing:

• assignment — "all", "unassigned", "assigned"
• create_reservation.type — 10 reservation types
• update_reservation.type — same 10 types
• update_reservation.status — "pending", "confirmed", "cancelled"

Error handling

• MCP transport requests wrapped in try/catch — crashes now log actual errors instead of silently failing
• All broadcast() calls wrapped in safeBroadcast() to prevent WebSocket errors from crashing tool handlers

Bug Fixes

Bug	Description	Fix
Connection exhaustion	After ~3 write calls, server stopped responding entirely	Fixed safeBroadcast recursive bug; streaming requests no longer crash the MCP
update_place missing fields	category_id, osm_id, price, currency, place_time, end_time, duration_minutes, transport_mode not in tool schema	Added all fields to tool schema, handler, and service UPDATE
create_collab_note ignores pinned	pinned: true silently ignored	Added pinned to createNote service INSERT and tool schema
osm_id silently ignored on update	Service UPDATE didn't include osm_id	Added osm_id to UPDATE statement and tool schema

Pre-existing Bugs Confirmed Working

• create_place, update_place, list_places, get_trip_summary, list_trips, list_categories, search_place, assign_place_to_day, delete_place — all verified working
• create_budget_item, create_packing_item, create_reservation — working (were failing before safeBroadcast fix)

Test Results

• 513 unit tests: all pass ✅
• Perplexity MCP integration: 50+ consecutive tool calls with no crashes ✅
• Manual curl testing: all filter modes work correctly ✅

Commits (10 total)

Commit	Description
9510fba	feat: add list_places assignment filter for orphan activities
f5777ff	fix: document assignment enum values in list_places description
d15b837	fix: add describe() to remaining z.enum fields
57c0108	fix: add error handling and logging to prevent silent crashes
e7206dc	fix: wrap broadcast calls in try-catch to prevent WebSocket errors crashing tools
a5c7a49	fix: revert allowedOrigins to avoid SDK compatibility issues
52e2f7f	fix: safeBroadcast now calls broadcast correctly (was recursive call bug)
7d9455b	fix: add missing fields to update_place and create_collab_note pinned support
910159f	fix: add osm_id to update_place

Disclaimer: Entirely vibe coded with MiniMax M2.7.

[mauriceboe]

Manual approved today

[jubnl]

I had some minor improvements to do, closing this pr in favor for #535