Sign in with Excitor Core or an etpl_ key only; fix lead-to-plan workflow bugs
Sign-in:
- The login screen offers only Sign in with Excitor Core and an etpl_ key. Email/password sign-in, the sign-up form and the admin "set password" box are removed, with their routes.
- Every key starts with etpl_, and the server refuses any other key, including BRD_API_KEY / BRD_ANALYST_KEY. Opening the access store revokes older keys and drops stored passwords.
- Sign-up settings now only govern a person's first Excitor Core sign-in.
- Deploy docs and the compose hint generate etpl_ keys.
Workflow fixes (lead -> BRD -> FRD -> implementation plan):
- Brief: refuse auto-fill values citing sources that don't exist, keep picked modules, keep sources when a refill fails, keep a disconnected Zoho org visible. Refreshing a BRD keeps its depth and client family.
- FRD: an older version can't be approved over a newer one, revisions don't inherit lineage links, a meeting lookup failure no longer blocks creation, stores recover from a failed read and save only changed rows, plus workspace/library UI race fixes.
- Plan: keep grouped workflow criteria, survive non-object configuration, merged items with open questions are manual, break dependency cycles, reconcile leaves never-attempted runs partial, and metadata-only build saves create a new version.
- Browser workflow test no longer picks up Core sign-in from a local .env.