chore: add review instructions, PR template, and .ai gitignore

- copilot-instructions.md: Rust/UniFFI-specific code review rules
- pull_request_template.md: standard PR template (Description, Preview, QA Notes)
- .gitignore: add .ai for Claude-generated files

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ovitrif

.github/copilot-instructions.md

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+# GitHub Copilot Code Review Instructions
+
+When performing a code review, respond in English.
+
+## Architecture & Patterns
+
+When performing a code review, ensure new public types are properly exported via `src/lib.rs` for UniFFI binding generation.
+
+When performing a code review, verify that modules follow the established structure: `mod.rs`, `types.rs`, `errors.rs`, `implementation.rs`, and optional `tests.rs`.
+
+When performing a code review, check that UniFFI-exported types follow existing patterns (derive macros, enum representations, error types).
+
+## Error Handling & Safety
+
+When performing a code review, flag any use of `unwrap()` or `expect()` in non-test code and suggest proper error propagation with `?` or `Result`.
+
+When performing a code review, ensure error types implement proper `Display` and `Error` traits and are exported for UniFFI.
+
+When performing a code review, flag any `unsafe` blocks and verify they are necessary and well-documented.
+
+## Code Quality & Readability
+
+When performing a code review, ensure `cargo clippy` warnings are addressed — the project treats clippy warnings as errors.
+
+When performing a code review, verify that `cargo fmt` formatting is applied consistently.
+
+When performing a code review, focus on readability and avoid deeply nested match arms, replacing with early returns or helper functions where possible.
+
+When performing a code review, ensure unused code is removed after refactoring.
+
+When performing a code review, verify that existing utilities and helper functions are reused rather than creating duplicates.
+
+## Dependencies & Platform
+
+When performing a code review, verify that platform-specific dependencies use correct `#[cfg(target_os)]` guards (especially Trezor: BLE-only on iOS, USB+BLE elsewhere).
+
+When performing a code review, check that new dependencies are justified and don't introduce unnecessary bloat to the FFI binary.
+
+## Testing
+
+When performing a code review, suggest tests for new functionality covering the most important cases.
+
+When performing a code review, verify that tests use the established patterns (test modules in `tests.rs`, `#[cfg(test)]` gating).
+
+## Bitcoin & Lightning Specific
+
+When performing a code review, verify that Bitcoin/Lightning operations use proper types from the `bitcoin` and `bdk` crates.
+
+When performing a code review, verify that proper Bitcoin and Lightning technical terms are used when naming code components.
+
+## Build & Version
+
+When performing a code review, check that version changes are synchronized across `Cargo.toml`, `Package.swift`, and `bindings/android/gradle.properties`.
+
+When performing a code review, verify that changes to public API types don't break existing UniFFI bindings without updating the binding generation.

.github/pull_request_template.md

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+<!-- Closes | Fixes | Resolves #ISSUE_ID -->
+<!-- Brief summary of the PR changes, linking to the related resources (issue/design/bug/etc) if applicable. -->
+
+### Description
+
+<!-- Extended summary of the changes, can be a list. -->
+
+### Preview
+
+<!-- Insert relevant screenshot / recording -->
+
+### QA Notes
+
+<!-- Add testing instructions for the PR reviewer to validate the changes. -->
+<!-- List the tests you ran, including regression tests if applicable. -->

.gitignore

@@ -1,3 +1,4 @@
 target/
 .idea/
 .DS_Store
+.ai