Issue #831 — Build UI Pages Resolve Project Scope (verification)

Child tracking sub-task of enhancement #503 ("builds scoped to the Test Project").

What this sub-task covered

The scoped deliverable (commit 748555985, Refs #831) makes the build UI pages operate in project scope now that builds carry their own testproject_id (added in #826):

• lib/plan/buildCopyExecTaskAssignment.php — init_args() resolves the owning test project directly from the build's testproject_id (lib/plan/buildCopyExecTaskAssignment.php:93-95) instead of walking the testplan node via get_node_hierarchy_info. tplan_id is read defensively (still populated by dual-write until #834 drops it).
• Build listing/selector methods in lib/functions/testplan.class.php are project-scoped, so a build is shared across the plans of its project:
  • get_builds_for_html_options() — WHERE testproject_id = getProjectIdOfPlan($id) (testplan.class.php:2076)
  • get_builds() / get_build_by_name() / get_max_build_id() / getNumberOfBuilds() / check_build_name_existence() — all project-scoped (lines 2127/2328/2377/2404/2431/2481/2523)

Investigation result — not a defect

A bug-fix pass was triaged onto #831 (oldest open issue without a work-type label — a label gap: this tracking sub-task should carry enhancement). After a fresh DB import, the deliverable is confirmed already landed on the default branch and correct:

DESCRIBE builds;          -> testproject_id int unsigned NO MUL (column exists, from #826)
git merge-base --is-ancestor 748555985 HEAD -> true

php tmp/repro_831_verify.php → 7/7 PASS
  init_args resolves tproject_id=2000 / tplan_id=2001 from the build row
  get_builds_for_html_options(plan 2001) and (plan 2002) both contain project build 3001
  check_build_name_existence is project-wide

There is no code defect. The remaining parent-#503 sub-tasks — dropping builds.testplan_id

• swapping the unique key (#834), the cross-plan per-build results report (#835), and the Test-Project-menu move (which is the body DoD of this very issue #831) — are owned by the modernize workflow and tracked separately (all still OPEN).