fixed all 3 issues

[bentechnology03-ops]

closes #253
closes #255
closes #256

SUMMARY:
Here's what changed: #253

lib.rs

Added InvalidFeeParams = 9 to Error
apply_fee now takes &Env as first argument and calls panic_with_error!(env, Error::InvalidFeeParams) when fee_bps > 10_000 or amount < 0 — same convention as every other guard in the contract
Rustdoc updated: both constraints are now described as rejected, not merely expected
test.rs

fee_plus_net_equals_amount passes &env and adds a net >= 0 assertion to nail down the no-negative-net invariant
rejects_fee_bps_above_10000 proptest: generates fee_bps in 10_001..=u32::MAX and asserts catch_unwind returns Err — apply_fee(10_001, x) can no longer return a negative net
rejects_negative_amount proptest: same pattern for amount < 0

#255
All good. Here's what changed:

lib.rs

LEDGER_THRESHOLD gets a rustdoc explaining it as the re-extension trigger threshold, with wall-clock conversion (100 ledgers ≈ 8 minutes at 5 s/ledger) and a description of how the Soroban host uses it
LEDGER_EXTEND_TO gets a rustdoc stating 500,000 ledgers ≈ 29 days, citing the network cap of 535,679 ledgers with a link to the Stellar CLI docs, explaining the intentional margin, and pointing operators to the README runbook for the dormant-circle case
A const _: () = assert!(LEDGER_THRESHOLD < LEDGER_EXTEND_TO, ...) compile-time assertion so a future edit that inverts the relationship fails at compile time, not silently at runtime
README.md

New "Storage lifetime" section placed just before the existing instance-storage archival paragraph, with a table showing both constants and their wall-clock equivalents, the network cap citation, a plain-English explanation of the 29-day activity window, and a concrete stellar contract restore runbook for the dormant-circle case

#256 :
All clean. Here's a summary of what changed across the three layers:

lib.rs
— four new read entrypoints, each reverting with CircleNotFound consistently with get_circle:

get_round(circle_id) -> u32
get_pot(circle_id) -> i128
get_status(circle_id) -> (u32, i128, i128, bool) — the one the poll loop uses; skips the VK entirely
get_contributors(circle_id) -> Vec

— for the cancel/refund UI
test.rs
— 8 new tests: a happy-path and a CircleNotFound revert for each of the four new entrypoints.

contract.ts
— wrappers getRound, getPot, getStatus (returning a typed CircleStatus), getContributors; also defined the missing withRetry helper that was already being called but never defined.

useCircleFlow.ts
and
App.tsx
— all getCircle poll calls replaced with getStatus. The top-level import, the two lazy dynamic imports in fundMember/doClaim/claimAgain, and the best-effort refresh in claimAgain's finally block are all switched over.