Hugo's Cryptic

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Across
  1. 4. Authoritative soldiers engaged in physical stuff (11)
  2. 7. Piece of shell amazes farm animal (5)
  3. 10. Careful owl eats one cooked vegetable (11)
  4. 11. Compound greek letter found in poem (5)
  5. 12. Thousands collecting software from Apple shop (5)
Down
  1. 1. Cool bug (3)
  2. 2. Clue Siri‘s dismantled about half of explosive warhead (6,7)
  3. 3. Scrounger as pirate in disguise (8)
  4. 5. President takes 50/50 and newspaper is optimistic (7)
  5. 6. Togo loses attempt to break embargo and gets stick (5)
  6. 8. Expert takes firsts in American cycling event (3)
  7. 9. Representative is specialist on mathematical variables (5)