fix(forecast,twist): https base_uri so writes don't die on the http->https redirect

[hhff]

The bug

Stacks::Forecast declared base_uri 'api.forecastapp.com' — no scheme, so HTTParty defaulted to http://. Forecast 301-redirects http → https. GETs survive the redirect (reads worked), but a redirected POST arrives malformed and Forecast returns 400 Bad Request. So:

• create_assignment raised on the 400, and RecurringAssignment#materialize!'s per-occurrence rescue => e; Sentry.capture_exception(e) swallowed it — no occurrence recorded, no Forecast assignment, nothing in the admin UI.
• This affects every Forecast write through the class: recurring-assignment materialization, the provisioning tools (create project/client/workstream/rate), and the write-through work. It passed CI the whole time because the tests stub the HTTP layer — it only surfaces against the live API.

Verified live (against the real account)

Request	Result
via the class (http → 301 → https)	400 Bad Request (malformed)
direct https://…/assignments, same body/headers	201 Created

The fix

One line each: base_uri 'https://api.forecastapp.com' and — same scheme-less pattern, also a writer — base_uri 'https://api.twist.com/api/v3'. Every other API client (Runn, Deel, Notion, Apollo) already used https://.

Added test/lib/stacks/https_base_uri_test.rb — a guard that fails if any HTTParty client's base_uri isn't https://, so this silent-write-failure class can't return.

Testing

Guard test fails on the old code (got "http://api.forecastapp.com"), passes after. Full test/lib/stacks suite green (284 runs, 0 failures). No behavior change for reads; writes now hit https directly instead of a mangling redirect.

🤖 Generated with Claude Code