Toronto Community Housing procurement (Bonfire + Biddingo)

Part of #103. Blocked on #103's keyspace and terms-of-use decisions.

## What exists

Toronto Community Housing posts procurement documents on **Bonfire** and **Biddingo** — `https://torontohousing.ca/partner-tchc/procurement-opportunities`, with a published procurement policy at `https://torontohousing.ca/policies/procurement-policy`.

TCHC's own procurement page is one of the few that returned **HTTP 200** to a plain client during the survey — worth knowing before anyone assumes a browser is needed.

## Why this one matters beyond its size

TCHC is the largest social housing landlord in Canada and a **corporation**, not an agency — its board is separate and its procurement never touches PMMD. Its capital repair backlog is a standing public-interest story, and the contracts behind it are exactly the thing this archive exists to keep. Our spine has **zero** TCHC rows; the string "TCHC" appears in **0** of 7,444 solicitations.

## Platform note

**Bonfire is shared with Waterfront Toronto (#108)** — same argument as MERX in #104: adapter, not scraper. Biddingo is a second, separate platform and may not be worth doing at all if Bonfire carries the same notices; check for overlap before writing anything.

## Sources

- https://torontohousing.ca/partner-tchc/procurement-opportunities
- https://torontohousing.ca/policies/procurement-policy
- https://www.biddingo.com/ (Toronto Community Housing Corporation buyer page)

Start with the keyspace and terms-of-use decisions in #103, then review the TCHC procurement page and the Bonfire context shared with Waterfront Toronto in #108. Check whether Bonfire already covers the notices on Biddingo before deciding the ingestion scope. Done means TCHC procurement coverage is added without duplicating overlapping notices.

Written by the indexing model from the issue text.