feat(CP-2): Mislaka file upload and parser

[ncamaa]

Summary

• Add POST /api/plans/:planId/mislaka/parse endpoint for parsing Mislaka "HaTmuna HaMle'a" Excel files
• Parser reads Sheet 1 ("My Products"), maps Hebrew column headers to English fields, infers pension plan types from Hebrew product names
• Handles header variations, formatted numbers (commas, currency symbols), and multiple status variants (active/inactive/frozen/closed)
• Uses memory-based multer upload (10MB limit, xlsx/xls only) - no temp files on disk
• Response matches the shape expected by the frontend (useParseMislaka hook), enabling removal of the client-side mock fallback
• Added to OpenAPI docs under "Mislaka" tag
• Added Hebrew character ignore rule to cspell config

New files

• src/api/mislaka/parser.ts - Core parser: header mapping, plan type inference, number/status parsing
• src/api/mislaka/mislakaModel.ts - Zod schemas for request params and response
• src/api/mislaka/mislakaService.ts - Service layer with plan ownership check
• src/api/mislaka/mislakaController.ts - Request handler with file/auth validation
• src/api/mislaka/mislakaRouter.ts - Express router with multer middleware and OpenAPI registration
• src/api/mislaka/__tests__/parser.test.ts - 15 unit tests for parser and plan type inference
• src/api/mislaka/__tests__/mislakaService.test.ts - 5 unit tests for service layer

Test plan

• pnpm test passes (264 tests, 20 new)
• pnpm build succeeds (tsc + tsup)
• pnpm spell - 0 issues
• Manual test: upload a real Mislaka Excel file via curl or frontend
• Verify frontend useParseMislaka hook works with the real endpoint (removes 404 mock fallback)