Could the Dari word--in at least some of its senses--reflect Turkic influence? The first element recalls Turkic çal- as in Republican Turkish çalmak, "to strike" and çalıştırmak, "to make work, set to work, run, start up".
Can't really comment, since I have no knowledge of Turkish.
It is interesting to note that the word چالان is found in Steingass's Persian-English dictionary. I would never have guessed that this word has anything to do with Persian.
Invoice, bill of lading; transportation.
And here is an entry from Platt's
H & P چالان चालान ćālān
[S. चालनं rt. चल्; or i.q. ćālānā
, q.v.], s.m. An invoice or way-bill, bill of lading; a list (of letters, &c. sent); a certificate of despatch; a remittance; a memorandum of money received and invested; a pass, a passport; clearance (of a ship); sending up or forwarding (a case, or a prisoner, &c. to a magistrate, &c.); transportation:—ćālān-dār
, s.m. The person who has charge of an invoice, the bearer of a despatch or remittance; an escort:—ćālān karnā
, v.t. To send up (a case, or a prisoner, &c. to a magistrate), to commit (a prisoner) for trial; to forward an invoice (of).
We should not be overly surprised to find Urdu words in Persian bearing in mind that Persian speaking peoples have a long history in India. After all if Urdu can have so many words of Persian origin, why can't Persian have a few too? Listening to Youtube videos, I have noticed this is especially true of Dari.
Here is an "extreme" example from a letter written by the Emperor Abu'l-Fath Jalal-ud-din Muhammad Akbar (1556-1605) to Vaalii-i-Ambar...
-این لاڈلاءِ من است normally written این لاڈلائے من است۔
H لاڙلا लाड़ला lāṛlā
, or लाड़िला lāṛilā
, q.v.+Prk. इल्लओ=S. इल+कः], adj. & s.m. (f. -ī
), Darling, dear, beloved; tenderly nurtured; petted, spoilt (child);—a darling, a pet; one tenderly nurtured (syn. nāz-parwarda
); a spoilt child.
Having said all this, I am still of the view that چالان is Indic.