refactor: migrar reportes a Typst con plantilla compartida y scripts

- Reemplazar plantillas Markdown por template/report.typ y template/main.typ
- Agregar primer reporte: respuesta-observaciones-avance-1
- Agregar scripts build.sh, preview.sh y common.sh con salida en pdf/
- Actualizar README y AGENTS.md; simplificar .gitignore

AGENTS.md

@@ -0,0 +1,24 @@
+# Agent instructions
+
+- Do not use Graphify in this repository or generate Graphify artifacts. Inspect
+  files directly with tools such as `rg` instead.
+- Do not commit or push unless the user explicitly requests that action. A request
+  to edit, fix, build, or test does not authorize a commit or push. Permission to
+  commit does not imply permission to push, and permission to push does not imply
+  permission to create a commit.
+- Preserve existing uncommitted changes. Do not stage unrelated work.
+- Work on the current branch. Create or switch branches only when explicitly asked.
+- Keep the README concise and in Spanish.
+- Keep templates and reports separate: shared styling in `template/report.typ`
+  and the reusable scaffold in `template/main.typ`; actual reports belong in
+  `reports/<slug>/main.typ`, with images in `figures/`. Use short, descriptive,
+  lowercase hyphenated folder names; keep the full internal title in the document.
+- Do not generate PDFs for files in `template/`; compile actual reports only.
+- Use `./scripts/build.sh` to validate changes against the first report, or pass the affected report
+  path. Existing PDFs must be preserved unless `--force` is explicitly supplied.
+  To validate source changes, use `./scripts/build.sh --force [path]`.
+  Save generated PDFs in the repository's root `pdf/` directory, named after the
+  report folder for `main.typ`, or the source filename for other `.typ` files.
+  Generated PDFs are local artifacts and must not be committed.
+- Use `./scripts/preview.sh [path]` to open the saved PDF (creating it only if
+  missing). With `--force`, it regenerates and watches until Ctrl+C.