package .bin/ scripts as proper nix packages, delete .bin/

Packaged 14 scripts from .bin/ into packages/ with proper dependency
declarations (writers.writeDashBin/writeBashBin/writePython3Bin):
- 256color → two56color (terminal color chart)
- avesta.sed → avesta (Avestan transliteration)
- bvg.sh → bvg (Berlin transit disruptions)
- unicode → charinfo (Unicode character info)
- chunk-pdf → chunk-pdf (split PDFs by page count)
- csv2json → csv2json (CSV to JSON converter)
- fix-sd.sh → fix-sd (exFAT SD card recovery, improved output handling)
- json2csv → json2csv (JSON to CSV converter)
- mp3player-write → mp3player-write (audio conversion for MP3 players)
- mushakkil.sh → mushakkil (Arabic diacritization)
- nix-haddock-index → nix-haddock-index (GHC Haddock index generator)
- pdf-ocr.sh → pdf-ocr (OCR PDFs via tesseract)
- prospekte.sh → prospekte (German supermarket flyer browser)
- readme → readme (GitHub README as man page)

All added to overlay and packages output. .bin/ directory removed.

packages/prospekte.nix

@@ -0,0 +1,77 @@
+# Browse and view German supermarket flyers (Lidl, Aldi, REWE, Kaufland, Netto)
+{
+  writers,
+  curl,
+  jq,
+  fzf,
+  zathura,
+  coreutils,
+  htmlq,
+  gnugrep,
+  gnused,
+  lib,
+}:
+writers.writeDashBin "prospekte" ''
+  export PATH=${lib.makeBinPath [ curl jq fzf zathura coreutils htmlq gnugrep gnused ]}:$PATH
+
+  lidl() {
+    echo LIDL
+    curl -sSL 'https://endpoints.lidl-flyer.com/v3/region-overview/lidl/de-DE/0.json' \
+      | jq -r '
+        .categories
+        | map(select(.name == "Filial-Angebote") | .subcategories | map(.flyers))
+        | flatten
+        | flatten
+        | .[]
+        | .pdfUrl
+      '
+  }
+
+  aldi_nord() {
+    echo ALDI nord
+    echo 'https://magazine.aldi-nord.de/aldi-nord/aldi-aktuell/GetPDF.ashx'
+    echo 'https://magazine.aldi-nord.de/aldi-nord/aldi-vorschau/GetPDF.ashx'
+  }
+
+  rewe_berlin() {
+    store_id=662366923
+    publisher_id=1062
+
+    echo REWE
+    curl -sSL "https://www.bonialserviceswidget.de/de/stores/$store_id/brochures?storeId=$store_id&publisherId=$publisher_id" | while read -r brochure_id; do
+      curl -sSL "https://www.bonialserviceswidget.de/de/v5/brochureDetails/$brochure_id?publisherId=$publisher_id" | jq -r .pdfUrl
+    done
+  }
+
+  kaufland() {
+    region_code=8920
+    echo KAUFLAND
+    curl -sSL https://filiale.kaufland.de/prospekte.html | htmlq --attribute href '.flyer a' | grep -Eo 'DE_de_KDZ[^/]*' | sed "s/_3000_/_''${region_code}_/" | while read -r flyer_id; do
+      curl -sSL "https://endpoints.leaflets.kaufland.com/v3/$flyer_id/flyer.json?regionCode=$region_code" | jq -r .flyer.pdfUrl
+    done
+  }
+
+  netto_schwarz() {
+    echo 'NETTO (schwarz)'
+    curl -sSL 'https://squid-api.tjek.com/v2/catalogs?dealer_ids=90f2VL&order_by=created' \
+      | jq -r '.[] | .id' \
+      | while read -r flyer_id; do
+        curl -sSL "https://squid-api.tjek.com/v2/catalogs/$flyer_id/download" \
+          | jq -r .pdf_url
+      done
+  }
+
+  dir="$(mktemp -d)"
+  trap 'rm -rf "$dir"' EXIT
+
+  prospekt_url="$( (
+    lidl
+    aldi_nord
+    rewe_berlin
+    kaufland
+    netto_schwarz
+  ) | fzf)"
+
+  curl -sSL "$prospekt_url" -o "$dir/prospekt.pdf"
+  zathura "$dir/prospekt.pdf"
+''