feat: implement dispute raising function (raise_dispute)

[Akpolo]

Summary

Implements the raise_dispute entrypoint (issue #3): either party to an escrow — the depositor or the beneficiary — can halt release and call for a jury.

The core contract was an un-assembled scaffold (no lib.rs, no [package]), so this PR wires it into a buildable Soroban contract and implements the dispute logic on top of the existing types/storage/errors modules.

What it does

• Entrypoint (contracts/src/lib.rs): a #[contract] TrustFlowContract exposing raise_dispute(env, escrow_id, caller, reason).
• Logic (contracts/src/dispute.rs):
  • caller.require_auth();
  • only a party to the escrow (depositor or beneficiary) may raise — others get Unauthorized;
  • only an Active escrow can be disputed (→ Disputed, which halts release); a missing escrow → EscrowNotFound, a settled/already-disputed one → InvalidState (this also makes a second raise a no-op);
  • records a DisputeRecord for the jury and extends TTL;
  • emits a disputed event (topics (disputed, escrow_id), data raised_by) for indexers.
• Fix: storage.extend_ttl used a newer-SDK method; switched to the soroban-sdk 20 persistent TTL API (bump) and removed an unused import so the module compiles.

Tasks / acceptance criteria

• Implement Rust logic for the dispute-raising function
• Comprehensive unit tests (6): depositor & beneficiary can raise; outsider rejected; missing escrow, non-active escrow, and double-raise rejected; event emission asserted
• Proper event emission for indexing
• cargo fmt clean; cargo clippy clean (only upstream soroban-sdk macro cfg warnings remain)
• soroban/cargo build compiles to WASM without bloat — trustflow_core.wasm is ~10 KB

Test plan

cargo test -p trustflow-core            # 6 passed
cargo fmt -p trustflow-core -- --check  # clean
cargo clippy -p trustflow-core --all-targets
cargo build -p trustflow-core --target wasm32-unknown-unknown --release
cargo check --workspace                 # abundance + crowdfund still build

Note: the workspace pins soroban-sdk = 20.0.0-rc2, so the implementation uses the 20.x API and classic env.events().publish for the event. Wiring the other scaffold modules (settlement/fee/governance/oracle) and enforcing the Disputed guard on the release path are out of scope here and left for their own issues.

Closes #3

[meshackyaro]

Summary

Implements the raise_dispute entrypoint (issue #3): either party to an escrow — the depositor or the beneficiary — can halt release and call for a jury.

The core contract was an un-assembled scaffold (no lib.rs, no [package]), so this PR wires it into a buildable Soroban contract and implements the dispute logic on top of the existing types/storage/errors modules.

What it does

• Entrypoint (contracts/src/lib.rs): a #[contract] TrustFlowContract exposing raise_dispute(env, escrow_id, caller, reason).

• Logic (contracts/src/dispute.rs):

  • caller.require_auth();
  • only a party to the escrow (depositor or beneficiary) may raise — others get Unauthorized;
  • only an Active escrow can be disputed (→ Disputed, which halts release); a missing escrow → EscrowNotFound, a settled/already-disputed one → InvalidState (this also makes a second raise a no-op);
  • records a DisputeRecord for the jury and extends TTL;
  • emits a disputed event (topics (disputed, escrow_id), data raised_by) for indexers.

• Fix: storage.extend_ttl used a newer-SDK method; switched to the soroban-sdk 20 persistent TTL API (bump) and removed an unused import so the module compiles.

Tasks / acceptance criteria

• Implement Rust logic for the dispute-raising function
• Comprehensive unit tests (6): depositor & beneficiary can raise; outsider rejected; missing escrow, non-active escrow, and double-raise rejected; event emission asserted
• Proper event emission for indexing
• cargo fmt clean; cargo clippy clean (only upstream soroban-sdk macro cfg warnings remain)
• soroban/cargo build compiles to WASM without bloat — trustflow_core.wasm is ~10 KB

Test plan

cargo test -p trustflow-core            # 6 passed
cargo fmt -p trustflow-core -- --check  # clean
cargo clippy -p trustflow-core --all-targets
cargo build -p trustflow-core --target wasm32-unknown-unknown --release
cargo check --workspace                 # abundance + crowdfund still build

Note: the workspace pins soroban-sdk = 20.0.0-rc2, so the implementation uses the 20.x API and classic env.events().publish for the event. Wiring the other scaffold modules (settlement/fee/governance/oracle) and enforcing the Disputed guard on the release path are out of scope here and left for their own issues.

Closes #3

Fix conflicts and also ensure the CI passes

[meshackyaro]

Well done and thank you for your contribution.