Phase 1: Foundation Types (100% complete)
- query_helpers: SQL LIKE sanitization with pipe operators
- numeric: Integer parsing with pattern matching guards
- result: Pure Elixir Result monad (map, and_then, unwrap_or)
Phase 2: Ecto Domain Types (100% complete)
- ip_address: IPv4/IPv6 validation using :inet directly
- mac_address: Multi-format MAC parsing (colon/hyphen/dot/compact)
- snmp_oid: OID parsing/manipulation with recursive pattern matching
All 198 tests passing across converted modules.
API changed from Gleam-style {:some/:none to idiomatic {:ok/:error.
Refactored parse_numeric_oid to use with statement, reducing nesting depth.
Reviewed-on: graham/towerops-web#196
Migrate three pure-function modules from Elixir to Gleam:
- polling_offset: deterministic hash-based polling offset (pure Gleam, no FFI)
- changelog_parser: text parsing logic in Gleam, thin Elixir wrapper for File I/O
- user_agent_parser: regex-based UA parsing in Gleam with Erlang FFI for
atom-keyed map conversion
Add gleam_regexp dependency for regex support in Gleam modules.
Update all call sites and tests to use Gleam module atoms.
Reviewed-on: graham/towerops-web#103
