fix: use z.coerce.number() for numeric tool parameters

[aborruso]

Problem

Numeric parameters (rows, page_size, start, limit, offset, etc.) are defined with z.number() in Zod schemas. Some MCP clients pass these values as JSON strings instead of numbers, causing validation errors:

MCP error -32602: Input validation error:
  "code": "invalid_type",
  "expected": "number",
  "received": "string",
  "path": ["rows"]

Affected files

• src/tools/package.ts — 11 occurrences (rows, start, facet_limit, page, page_size, content_recent_days, limit, boost weights)
• src/tools/organization.ts — 2 occurrences (limit, offset)
• src/tools/datastore.ts — 2 occurrences (limit, offset)

Fix

Replace z.number() with z.coerce.number() for all numeric tool parameters. Zod's coerce converts string "3" → number 3 transparently, with no behavioral change when the value is already a number.

Reproduction

Call ckan_package_search with rows: "3" (string) via a local stdio MCP client — validation fails. The hosted version already handles this correctly.