What is written about the divine year, solar year, or human year in Surya Siddhanta, Mahabharata and Manusmriti?

Aindavastithibhiḥ tadvatsankrāntyā saur ucyate।
Māsair dvādaśabhir varṣa divyaṁ tadaha ucyate॥

- Surya Siddhanta (1.13)

According to this shloka, it is proved that in Surya Siddhanta, only the solar year is considered a divine year and not any other.

Tadvādaśasahasrāṇi caturyugam udāhṛtam।
Sūryābdasaṅkhyayā dvitrisāgarairayutāhataiḥ॥

Sandhyāsandhyāṁśasahitaṁ vijñeyaṁ taccaturyugam।
Kṛtādīnāṁ vyavasthēyaṁ dharmapādavyavasthayā॥

- Surya Siddhanta (1.15)

All four yugas together constitute 12000 years of a solar year. This is the system of all four yugas together with Sandhya and Sandhyansh.

Ahorātre vibhajate sūryo mānuṣadaivike।
Rātriḥ svapnāya bhūtānāṁ ceṣṭāyai karmaṇāmahaḥ॥

- Manusmriti (1.65)

That is, the Sun divides the day and night of humans and gods. It is clear from this verse that the Yuga calculation has been done in human years (i.e. solar years) and not in divine years.

Ye te rātryahani pūrvaṁ kīrtite jīvalaukike।
Tayoḥ saṅkhyāya varṣāgraṁ brāhme vakṣyāmyahaḥ kṣape॥

Mahabharata Shanti Parva, Chapter 231, Verse 18

That is, Chaturyuga has been calculated according to the number of human worlds.