Fix/q96 decoding precision [WIP don't merge]

[rdave8]

Summary by CodeRabbit

• New Features
  • Expanded supported price boundaries, enabling prices from approximately 0.000001 to 1,000,000.
  • Improved maker order price-range handling with protocol-aligned tick validation.
• Bug Fixes
  • Improved fixed-point price conversion accuracy, especially for fractional values and extreme price ranges.
  • Added validation to reject invalid or incorrectly ordered maker price bounds.
• Tests
  • Added coverage for boundary prices, tick alignment, valid ranges, and invalid maker configurations.

[coderabbitai]

📝 Walkthrough

Walkthrough

Protocol price and maker tick bounds are widened to approximately 1e-6–1e6. Q96 decoding is reworked to preserve integer and fractional components, while maker opening uses centralized aligned-tick validation with expanded boundary tests.

Changes

Protocol bounds and maker validation

Layer / File(s)	Summary
Protocol price and tick boundaries src/constants.rs, src/math/tick.rs	Factory sqrt-price constants and maker tick limits change to the new protocol range, with updated boundary assertions.
Q96 price conversion and boundary coverage src/convert.rs	price_x96_to_f64 uses quotient and remainder conversion, and tests cover prices from approximately 1e-6 through 1e6.
Maker tick derivation and validation src/client/trades.rs	open_maker delegates aligned tick calculation and validates protocol bounds, ordering, and invalid price ranges through new unit tests.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• StrobeLabs/perpcity-rust-sdk#71: Updates the same maker tick bounds and open_maker validation behavior.

Suggested reviewers: praz314159

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title matches the main change by describing the q96 decoding precision fix, even though it includes extra WIP text.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/q96-decoding-precision

---

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

🧹 Nitpick comments (1)

src/convert.rs (1)

182-194: 🎯 Functional Correctness | 🔵 Trivial | ⚡ Quick win

Add a mixed integer-and-fractional Q96 regression test.

Current tests exercise Q96, Q96 / 2, and integral multiples, but not the new reconstruction path with both components present. Add Q96 + Q96 / 2 and assert 1.5.

Proposed test

#[test]
fn price_x96_combines_integer_and_fractional_components() {
    let price = price_x96_to_f64(Q96 + Q96 / U256::from(2u64)).unwrap();
    assert!((price - 1.5).abs() < Q96_PRECISION);
}

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/convert.rs` around lines 182 - 194, Add a regression test for the
price_x96_to_f64 conversion that passes Q96 + Q96 / U256::from(2u64) and
verifies the result is approximately 1.5 using the existing Q96_PRECISION
tolerance. Name the test price_x96_combines_integer_and_fractional_components
alongside the current conversion tests.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@src/convert.rs`:
- Around line 182-194: Add a regression test for the price_x96_to_f64 conversion
that passes Q96 + Q96 / U256::from(2u64) and verifies the result is
approximately 1.5 using the existing Q96_PRECISION tolerance. Name the test
price_x96_combines_integer_and_fractional_components alongside the current
conversion tests.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 34d56beb-7cf8-4ce0-ad12-e2ca503e17aa

📥 Commits

Reviewing files that changed from the base of the PR and between e6aaa24 and 56b1840.

📒 Files selected for processing (4)

• src/client/trades.rs
• src/constants.rs
• src/convert.rs
• src/math/tick.rs