Add BabyCenter mirror site

[Sun-sunshine06]

Summary

• Adds a BabyCenter mirror under sites/babycenter with pregnancy week-by-week pages, baby month-by-month pages, a due date calculator, articles, community threads, login/profile tracker, and saved items.
• Seeds 37 pregnancy weeks, 25 baby months, 12 articles, 6 community posts, and 4 benchmark users.
• Registers babycenter as the next site on the upstream 15-site base, exposed on port 40015.
• Adds Docker build-time seed generation for the code-generated SQLite seed DB.

Verification

• sites/babycenter/venv/Scripts/python.exe -m py_compile sites/babycenter/app.py
• python -m py_compile control_server.py
• tasks.jsonl JSON parse check passed
• Flask test client smoke: /, /pregnancy/week-by-week, /pregnancy/week-18, /baby/month-by-month, /baby/month-6, /due-date-calculator, /articles, /community, /search?q=anatomy+scan, /login all returned 200
• Due date calculator POST returned an estimated due date
• Login as alice.j@test.com and save article flow returned 200
• Local seed byte-identity check: instance/babycenter.db matched instance_seed/babycenter.db after a second import

Note

• This branch is based on aiming-lab/WebHarbor main and does not include fork-only site changes.

[Susan571]

Reviewer checklist (WebHarbor Review Guide)

Reviewer note: Source-level review (checked out pull/42/head). The mechanical Docker pipeline (build, curl 200, md5 reset) was not run in my environment — please pair with a Docker-capable mechanical pass.

Visual fidelity: ❌ FAIL

• Sensible IA (week-by-week, month-by-month, due-date calculator, articles, community), but all images come from the /illustration/<kind>/<slug>.svg placeholder generator. No real BabyCenter imagery → fails the real-images check.

Functional depth: ✅ PASS

• 37 pregnancy weeks + 25 baby months, a working due-date calculator (POST computes the week), trimester-filtered articles, community threads, login, profile/tracker, save-article. Auth + CRUD + a real computed tool — good depth.

Task quality: ⚠️ Request changes (10 tasks)

• Reasonable content-reading tasks: BabyCenter--0 (baby size at week 18), --3 (search "anatomy scan" → article), --4 (month-6 sleep guidance), --7 (June 2026 Birth Club reply count).
• Good multi-step/state tasks: --1 (due-date calculator with given LMP/cycle), --6 (update tracker due date, confirm the week changes).
• Only 10 tasks (need 15–20); BabyCenter--5 leaks the password; confirm searched-article titles don't already contain the asked answer on the results card.

Verdict: Request changes

(1) Use real images; (2) provide 15–20 tasks; (3) remove the credential leak; (4) verify card-vs-detail answer placement so search results don't surface answers.