docs: reflect bundled Tesseract on every install surface

- NEW LICENSE_TESSERACT.txt at the repo root: header noting it covers
  the bundled Tesseract OCR binary (Apache 2.0, upstream
  tesseract-ocr/tesseract, copyright Google + contributors) and the
  eng.traineddata from tessdata_best (also Apache 2.0). Clarifies
  DataTools itself remains proprietary. Full canonical Apache 2.0
  license text included.
- README.md + README.es.md (Download section): bumped size estimate
  ~200 MB → ~300 MB, added a short paragraph stating Tesseract OCR
  is bundled (no separate install required), with a link to the new
  license file.
- docs/USER-GUIDE.md + docs/USER-GUIDE.es.md (§1.6 System
  requirements): bumped disk estimate, added a paragraph stating
  Tesseract 5.5 + eng.traineddata ship inside every installer /
  portable / AppImage, with a source-install fallback hint pointing
  developers to DEVELOPER.md.
- docs/DEVELOPER.md: new "PDF Extractor — bundled Tesseract" section
  documenting the runtime layout (sys._MEIPASS / tesseract / …),
  discovery order, source of bytes (build/vendor/tessdata + per-
  platform fetch in make_release.py), version pin, update recipe.
- docs/TECHNICAL.md: new §3.10 "Bundled Tesseract (PDF Extractor
  OCR)" — short version of the discovery order for the build
  pipeline section.
- build/README.md: distribution-outputs paragraph now lists
  Tesseract among bundled deps with the ~250-300 MB estimate; new
  "Tesseract bundling" section: layout diagram, resolver order,
  source of bytes + 5.5.0 pin, update steps, license-file ref.

Out-of-scope gaps noted by the docs sweep:
- docs/FUTURE-TOOLS.md §D still describes Tesseract bundling as a
  high-risk packaging headache; now superseded. Worth a one-line
  "(resolved — bundled as of v1.x)" callout in a future pass.
- USER-GUIDE §2 "What's included" table doesn't list PDF Extractor
  at all (it shipped in b8aff86…967d3f6). Separate gap to close.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.es.md

@@ -30,7 +30,9 @@ Paquetes precompilados — sin instalar Python, sin permisos de administrador, s
 | **Windows** | `DataTools-X.Y.Z-win-setup.exe` — ejecuta el instalador (por usuario, sin admin). Crea acceso directo en el escritorio + entrada en el menú Inicio. | `DataTools-X.Y.Z-win-portable.zip` — descomprime donde quieras, doble clic en `DataTools.exe`. |
 | **Linux** | `DataTools-X.Y.Z-linux-x86_64.AppImage` — `chmod +x` y doble clic. | El AppImage ya es portable. |
 
-Última versión: consulta [GitHub Releases](https://git.invixiom.com/giteadmin/datatools-dev/releases) (o el listado de Gumroad). Cada paquete ocupa ~200 MB descomprimido; al primer arranque la app levanta un servidor local en http://127.0.0.1:8501 y abre tu navegador predeterminado. Nada sale de tu equipo — instalador y portable son idénticos por dentro.
+Última versión: consulta [GitHub Releases](https://git.invixiom.com/giteadmin/datatools-dev/releases) (o el listado de Gumroad). Cada paquete ocupa ~300 MB descomprimido; al primer arranque la app levanta un servidor local en http://127.0.0.1:8501 y abre tu navegador predeterminado. Nada sale de tu equipo — instalador y portable son idénticos por dentro.
+
+**Tesseract OCR viene incluido.** El soporte para PDFs escaneados del Extractor de PDF funciona sin configuración adicional en las tres plataformas — no hace falta instalar Tesseract por separado. Atribución de licencia: ver [`LICENSE_TESSERACT.txt`](LICENSE_TESSERACT.txt).
 
 **Avisos del primer arranque (una sola vez):**
 - **macOS** sin firma: clic derecho → **Abrir** → confirma. (Las compilaciones firmadas se lo saltan.)