Reseam as callista-odoo-demo: source-agnostic discovery, parallel build, follow-through

Callista consumes this pipeline for both plain Odoo implementations and
vertical demos, and is not a maintainer upstream — so the generic demo craft
that had accumulated in the buildease-demo vertical skill lands here instead,
where every engagement can reach it.

Moved in from buildease-demo (they were never construction-specific):
- Phase A: discovery brief from a transcript, notes, email, Knowcap, or a
  batched interview. Replaces the Knowcap-bound step 1. Infers before it asks.
- Fork the slow half: instance prep and client research as two parallel
  subagents, then join.
- Purge test residue: ordering, traps, read-back-the-counts evidence.
- Phase C: objection sheet, scoped quote, implementation timeline, SOW.

New here:
- Extension points — a vertical supplies module routing, solution precedence,
  purge chain, demo-data policy and follow-through framing, and nothing else.
  Anything it needs beyond those is a gap to fix here, not to work around.
- Named steps instead of numbered ones. Numbering meant an upstream renumber
  silently misrouted an extending skill with nothing to detect it.

Renamed the skill to callista-odoo-demo: skills resolve by directory name, so
a same-named fork shadows upstream depending on install order, and two people
would build different demos from the same brief.

MIT retained; SMEtools copyright kept, Callista added for modifications.
Fork point and divergence recorded in UPSTREAM.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

LICENSE

@@ -1,6 +1,7 @@
 MIT License
 
 Copyright (c) 2026 SMEtools
+Copyright (c) 2026 Callista BV (modifications)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal