refactor: replace float32/number identifiers with integer types

[electather]

Summary

Replace all hand-written float32 flag types and ParseFloat calls with integer types throughout CLI handlers and MCP tool handlers. The auto-generated pkg/api/ client still uses float32 for API parameters; float32(id) casts remain only at those API call boundaries.

Closes #69

Changes

Step 1 — CLI positional arg parsing

• Replaced strconv.ParseFloat(args[0], 32) with strconv.ParseInt(args[0], 10, 64) for all commands that accept a numeric ID as a positional argument (movies, tv, users, person, collection, service, issue, tmdb, other, overriderule)
• Season numbers in request create/update now also use ParseInt (the []float32 slice stays because the generated API requires it)

Step 2 — Cobra flag types

• Changed all cmd.Flags().Float32("xxx", ...) / GetFloat32("xxx") flag registrations to Int for pagination params (--page, --take, --skip), ID params (--media-id, --tmdb-id, --requested-by, --server-id, --profile-id, --language-profile-id, --user-id, --tvdb-id, --network, --studio, --permissions, etc.)

Step 3 — MCP tool handlers

• Replaced req.RequireFloat → req.RequireInt and req.GetFloat → req.GetInt for all integer IDs and pagination parameters in all MCP tool files

Step 4 — GenreMap

• Changed GenreMap key type from float32 to int in cmd/mcp/enrich.go

Test plan

• go test -v ./... passes
• go fmt ./... produces no diff
• go build succeeds
• New tests in tests/int_flags_test.go verify decimal IDs and --page flags are now rejected with a parse error

Checklist

• New tests added for new behaviour
• Documentation updated (README, command --help, comments)
• No unrelated changes included