Write Mock Client #2 brief (HVAC)

## Mock Client #2: [Name TBD] HVAC Same format as Mock Client #1 brief. Include: - [ ] Business name, location, owner name/personality - [ ] Services offered (heating, cooling, maintenance, emergency, installation) - [ ] What they want: multi-page site to generate leads - [ ] Budget expectations - [ ] Brand preferences - [ ] Competitors - [ ] What "success" looks like Store at: data/projects/otf-3-training-roadmap/mock-client-2-hvac.md