build: drop the local Python release method, return to CI-only installer builds

Removes the single-command Python packaging method (build/make_release.py
+ build/build_portable_zip.py + build/macos/build_zip.sh) and the portable
.zip artifacts it produced. Release builds go back to the original GitHub
Actions process: the CI matrix builds one installer per platform (.dmg /
.exe / .AppImage) on tag push and attaches them to a GitHub Release.

Tesseract OCR bundling is preserved: the fetch helpers the workflow depends
on (fetch_tessdata, fetch_tesseract_for_platform) are extracted into a
standalone build/tesseract.py, which build.yml now imports.

Docs (README, build/README, DEVELOPER, TECHNICAL, USER-GUIDE, vendor README,
es translations) updated to drop the portable-zip flavor and point at the
new module.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

build/macos/build_zip.sh

@@ -1,43 +0,0 @@
-#!/usr/bin/env bash
-# Wrap dist/DataTools.app into a no-install portable .zip.
-#
-# Usage:
-#   bash build/macos/build_zip.sh <version>
-#
-# Why a portable .zip in addition to the .dmg:
-#   * Buyers who don't want an installer can unzip and double-click the
-#     .app directly — no drag-to-/Applications step, no installer
-#     chrome. Self-contained: the .app holds Python + every dep.
-#   * IT-locked-down machines often block .dmg auto-mount but allow
-#     .zip download + extraction.
-#
-# Run after ``pyinstaller build/datatools.spec --clean --noconfirm``
-# has produced ``dist/DataTools.app``. Output goes to
-# ``dist/DataTools-<version>-mac-portable.zip``.
-#
-# Tesseract bundling: no-op here. The bundled Tesseract binary +
-# dylibs + tessdata are already inside DataTools.app/Contents/Resources/tesseract/
-# (placed by PyInstaller's BUNDLE/datas mechanism). ``ditto -c -k``
-# preserves the whole .app tree.
-
-set -euo pipefail
-
-VERSION="${1:-0.0.0-dev}"
-APP="dist/DataTools.app"
-ZIP="dist/DataTools-${VERSION}-mac-portable.zip"
-
-if [[ ! -d "$APP" ]]; then
-  echo "Error: $APP not found. Run pyinstaller build/datatools.spec first." >&2
-  exit 1
-fi
-
-# ``ditto`` preserves the .app bundle's extended attributes and
-# resource forks (a plain ``zip`` strips them and can break code
-# signatures + Info.plist resolution on the buyer's machine).
-#
-# --sequesterRsrc keeps the AppleDouble metadata inside the archive
-# rather than as parallel ._ files on disk after extraction.
-rm -f "$ZIP"
-ditto -c -k --sequesterRsrc --keepParent "$APP" "$ZIP"
-
-echo "Built $ZIP ($(du -h "$ZIP" | cut -f1))"