[Contracts] LoanManager approve_loan overrides the borrower-requested term with the default term

[grantfox-oss]

Telegram (ask questions / claim the issue here first): https://t.me/+DOylgFv1jyJlNzM0

Why this matters

request_loan in loan_manager/src/lib.rs validates and stores term_ledgers: term from the borrower, but approve_loan overwrites it with let term_ledgers = Self::read_default_term(&env); and sets loan.term_ledgers = term_ledgers / due_date = sequence + term_ledgers. The borrower's requested and validated term is discarded, and min/max term limits checked elsewhere never bind the actual approved term.

Acceptance criteria

• Approve using the loan's stored term_ledgers (or document why the default overrides it and enforce min/max term at request time accordingly)
• Ensure min_term/max_term limits validated in request_loan actually govern the approved due_date
• Add a test that requests a non-default term and asserts the approved loan's due_date reflects it
• Update request_loan/approve_loan doc comments to match the real behavior

Files to touch

• loan_manager/src/lib.rs

Out of scope

• Adding variable-rate terms
• Refinance term semantics

[david87131]

I have reviewed the issue and the surrounding code and I am confident I can deliver it. My approach is to keep the diff small, match the existing patterns in the repo, and include a test before opening the PR. I can have it up for review within 3 days.

[grantfox-oss]

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[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@david87131's PR #34 was approved and merged by @ogazboiz.

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👏 Great work, @david87131! Keep contributing to LabsCrypt.