chore: Fix rustc 1.91.1 warnings

[kpp]

Description

This is a forward compatible fix of warnings for rustc 1.91.1. This change produces no warnings neither for 1.88 nor 1.91.1, so it is safe to use 1.91.1 locally without upgrading the CI and ecosystem to 1.91.1:

$ git diff rust-toolchain.toml
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 0498c6bf5..4f5fb39a0 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,4 +1,4 @@
 [toolchain]
-channel = "1.88"
+channel = "1.91.1"
 components = ["rustfmt", "rust-src", "clippy"]
 profile = "minimal"

Fixes

Recent rust-analyzer upgrade.

[Copilot]

Pull request overview

This PR addresses Rust compiler warnings introduced in rustc 1.91.1 by making forward-compatible changes that work with both Rust 1.88 and 1.91.1. The changes modernize the codebase to align with newer Rust idioms and compiler expectations without introducing breaking changes.

Key changes include:

• Explicit lifetime annotations in function return types to satisfy stricter lifetime elision rules
• Reordering of Ord and PartialOrd trait implementations to follow the idiomatic pattern
• Replacing manual Default implementation with derive macro using #[default] attribute
• Using is_multiple_of method instead of modulo operator for divisibility checks

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/sovereign-sdk/rollup-interface/src/state_machine/da.rs	Reorders Ord and PartialOrd implementations to follow idiomatic pattern where PartialOrd delegates to Ord
crates/sovereign-sdk/module-system/sov-modules-core/src/storage/scratchpad.rs	Adds explicit lifetime annotations to accessory_state and offchain_state return types
crates/sovereign-sdk/module-system/sov-modules-api/src/lib.rs	Simplifies HashMap type parameter by removing redundant parentheses around trait object
crates/sovereign-sdk/full-node/db/sov-schema-db/tests/iterator_test.rs	Adds explicit lifetime annotations to iter and rev_iter return types
crates/sovereign-sdk/full-node/db/sov-schema-db/src/schema_batch.rs	Adds explicit lifetime annotations to iterator return types in iter and iter_range methods
crates/sovereign-sdk/full-node/db/sov-schema-db/src/lib.rs	Adds explicit lifetime annotations to various iterator-returning methods
crates/light-client-prover/src/circuit/initial_values.rs	Adds explicit lifetime annotations to initial_batch_proof_method_ids return types
crates/bitcoin-da/src/service.rs	Replaces manual Default implementation with derive macro using #[default] attribute
crates/bitcoin-da/src/helpers/merkle_tree.rs	Replaces % 2 == 0 with is_multiple_of(2) method for divisibility check

---

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[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.6%. Comparing base (f8622d5) to head (031e3d3).

Files with missing lines	Patch %	Lines
.../light-client-prover/src/circuit/initial_values.rs	50.0%	1 Missing ⚠️
...overeign-sdk/full-node/db/sov-schema-db/src/lib.rs	75.0%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
crates/bitcoin-da/src/helpers/merkle_tree.rs	100.0% <100.0%> (ø)
crates/bitcoin-da/src/service.rs	84.0% <ø> (-0.1%)	⬇️
...sdk/full-node/db/sov-schema-db/src/schema_batch.rs	100.0% <100.0%> (ø)
...reign-sdk/module-system/sov-modules-api/src/lib.rs	100.0% <100.0%> (ø)
...-system/sov-modules-core/src/storage/scratchpad.rs	92.8% <100.0%> (ø)
...reign-sdk/rollup-interface/src/state_machine/da.rs	69.3% <100.0%> (+3.4%)	⬆️
.../light-client-prover/src/circuit/initial_values.rs	47.2% <50.0%> (ø)
...overeign-sdk/full-node/db/sov-schema-db/src/lib.rs	78.0% <75.0%> (ø)

... and 2 files with indirect coverage changes

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