Implement query_festival MCP tool

[AngusHsu]

Description

Create the query_festival tool handler at src/tools/query-festival.ts and register it in the server.

Tool specification

• Name: query_festival
• Description: Query Chinese festival data by name, date, or tag
• Input schema (zod):
  • query (optional string) — search by festival name (Chinese or English, fuzzy match)
  • month (optional number) — filter by lunar month
  • day (optional number) — filter by lunar day
  • tag (optional string) — filter by tag
• Output: Matching festival(s) with full details (description, offerings, rituals, images)

Search behavior

• Name search: case-insensitive, partial match for both zh and en names
• Date search: exact match on lunar month/day
• Tag search: exact match on tag
• Multiple filters: AND logic
• No filters: return all festivals

Depends on

• Define Festival TypeScript types #4 (Festival types)
• Create seed data for major Chinese festivals #5 (Seed data)
• Implement MCP server setup and stdio transport #6 (MCP server setup)

Acceptance Criteria

• src/tools/query-festival.ts exports tool handler
• Tool registered in MCP server
• Searching by name returns correct results
• Searching by date returns correct results
• Searching by tag returns correct results
• No match returns empty with helpful message
• Build passes