fix: stop overriding CURRENT_PROJECT_VERSION with the CI run number

assemble was passing CURRENT_PROJECT_VERSION=$BUILD_NUMBER (github.run_
number-style CI counter) as an xcarg, silently replacing the project's
real, manually-managed version (e.g. '2026.09.11.0.0.1') with an
unrelated small integer - the just-uploaded TestFlight build showed up
as '0.0.1 (51)' instead of the intended version. Removed the override
and the now-unused BUILD_NUMBER env var in beta.yml; CI now always
builds with whatever CURRENT_PROJECT_VERSION is committed in the
project. Re-running CI against the same commit without bumping it first
will now get a clear 'duplicate build number' rejection from Apple
instead of silently uploading under the wrong version.

fastlane/Fastfile

@@ -16,10 +16,20 @@ lane :assemble do |options|
   # Manual signing (team/identity/profile) for the "PediFoods" target is
   # baked directly into PediFoods.xcodeproj's own project settings - not
   # overridden here.
-  # agvtool needs VERSIONING_SYSTEM = apple-generic, which this project doesn't
-  # set, so it silently no-ops - pass CURRENT_PROJECT_VERSION directly instead.
+  #
+  # CURRENT_PROJECT_VERSION is likewise never overridden here - it's
+  # whatever is committed in the project (manually bumped, e.g.
+  # "2026.09.11.0.0.1"). A prior version of this lane overrode it with
+  # the CI job's own run number (BUILD_NUMBER = github.run_number-style
+  # counter) to guarantee a unique, ever-increasing build number per
+  # run - but that silently replaced the real, meaningful version with
+  # an unrelated small integer (a build uploaded as "51" instead of the
+  # intended "2026.09.11.0.0.1"). Trusting the committed value means
+  # re-running CI against the same commit without bumping
+  # CURRENT_PROJECT_VERSION first will make TestFlight/App Store reject
+  # the upload as a duplicate build number - a clear, safe failure,
+  # which is the correct behavior for a manually-versioned project.
   xcargs = "-skipPackagePluginValidation -skipMacroValidation"
-  xcargs += " CURRENT_PROJECT_VERSION=#{ENV['BUILD_NUMBER']}" if ENV["BUILD_NUMBER"]
 
   build_app(
     scheme: "PediFoods",