The weekly seller update says how many showings the home had this week and what buyers' agents said #103

Intent: the seller's first question each week is "how did the showings go?", and the draft update answers it from the showings the agent logged.

Done looks like:

• [ ] The seller update draft (src/update.ts) adds a short showings paragraph for the last seven days: the count, how many were Interested or Offer likely, and each feedback line as the agent wrote it, without the buyer's agent's name; with none logged it says "No showings this week".
• [ ] The paragraph is Fair Housing checked like the rest of the update, and logging or removing a showing refreshes an unedited draft and clears its approval, the same way facts do today.
• [ ] Showings stay private everywhere else: still absent from the property page, flyer, email, launch kit and seller report.
• [ ] Tests in src/update.test.ts fail without the change: count and interest from sample showings, the empty week, a showing older than seven days left out, the agent name never in the text, approval cleared on a new showing.
• [ ] README step on the seller update mentions the showings paragraph in a realtor's words.

Files: src/update.ts, src/update.test.ts, possibly src/showings.ts and src/actions.ts, README.md.

Risks: leaking the buyer's agent name or a feedback line to a public surface; no contract change (the update is author-only already).

Suggested brief: a builder at home in the server modules (mason fits).