chore(key-wallet): drop no-std supp for key-wallet

[ZocoLini]

maybe is better to wait for key-wallet-manager to get merged into key-wallet

Summary by CodeRabbit

• Breaking Changes
  • The library now requires the Rust standard library and no longer supports no_std environments. Previously optional error trait implementations are now always available, and some conditional functionality is now unconditionally compiled.

[coderabbitai]

📝 Walkthrough

Walkthrough

This pull request systematically migrates the key-wallet crate family from alloc-based imports and no_std-compatible conditional compilation to unconditional std imports. It removes the std feature alias from Cargo configuration, inlines default feature dependencies, eliminates #[cfg(feature = "std")] guards from error and trait implementations, and replaces scattered alloc::* imports with std::* equivalents throughout the codebase.

Changes

Cohort / File(s)	Summary
Cargo Feature Configuration key-wallet/Cargo.toml, key-wallet-ffi/Cargo.toml, key-wallet-manager/Cargo.toml	Updated feature flags: key-wallet removes the std feature and inlines its dependencies into default. Dependents (ffi, manager) now rely on default features instead of explicit default-features = false + features = ["std"].
Core Library Setup key-wallet/src/lib.rs	Removed #![cfg_attr(not(feature = "std"), no_std)], extern crate alloc, extern crate core, and conditional extern crate std declarations.
Error Trait Implementations key-wallet/src/error.rs, key-wallet/src/bip32.rs, key-wallet/src/derivation_bls_bip32.rs, key-wallet/src/derivation_slip10.rs, key-wallet/src/psbt/error.rs, key-wallet/src/wallet/managed_wallet_info/coin_selection.rs, key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs, key-wallet/src/psbt/mod.rs	Removed #[cfg(feature = "std")] gating from impl std::error::Error for Error blocks, making error trait implementations unconditional.
Account Module Imports key-wallet/src/account/account_collection.rs, key-wallet/src/account/account_trait.rs, key-wallet/src/account/bls_account.rs, key-wallet/src/account/eddsa_account.rs	Switched BTreeMap and Vec imports from alloc::* to std::*, and removed unused alloc::vec::Vec imports.
BIP32 and Derivation Modules key-wallet/src/bip32.rs, key-wallet/src/derivation_bls_bip32.rs, key-wallet/src/derivation_slip10.rs	Removed conditional std error imports, made error trait implementations unconditional, and removed unused alloc::{string::String, vec::Vec} imports.
BIP38 and Related key-wallet/src/bip38.rs, key-wallet/src/derivation.rs	Removed unused alloc::{string::String, vec::Vec} imports.
Mnemonic Generation key-wallet/src/mnemonic.rs	Removed feature gating from pub fn generate_using_rng() and pub fn generate_with_seed(), making RNG-based mnemonic generation functions unconditional. Removed alloc::{String, Vec} imports and #[cfg(feature = "std")] guards.
Managed Account Core key-wallet/src/managed_account/mod.rs, key-wallet/src/managed_account/managed_platform_account.rs	Switched BTreeMap from alloc::collections to std::collections. Changed current_timestamp() from conditional std/no_std behavior to always use std::time::SystemTime::now() with unwrap_or_default().
Managed Account Collections key-wallet/src/managed_account/managed_account_collection.rs, key-wallet/src/managed_account/managed_account_trait.rs, key-wallet/src/managed_account/address_pool.rs, key-wallet/src/managed_account/metadata.rs, key-wallet/src/managed_account/transaction_record.rs	Switched BTreeMap from alloc to std. Removed unused alloc::{string::String, vec::Vec} imports.
PSBT Module key-wallet/src/psbt/mod.rs, key-wallet/src/psbt/map/global.rs, key-wallet/src/psbt/map/input.rs, key-wallet/src/psbt/map/output.rs, key-wallet/src/psbt/map/mod.rs, key-wallet/src/psbt/raw.rs, key-wallet/src/psbt/serialize.rs, key-wallet/src/psbt/error.rs	Consolidated imports from alloc::* to std::collections and removed unused alloc::{string::String, vec::Vec} imports. Simplified GetKey implementations by removing #[cfg(feature = "std")] gating. Updated test module imports.
Wallet Metadata and Config key-wallet/src/wallet/metadata.rs, key-wallet/src/wallet/root_extended_keys.rs, key-wallet/src/wallet/initialization.rs	Switched collection and string types from alloc::{borrow::Cow, collections::BTreeMap, string::String} to std equivalents.
Wallet Info Submodules key-wallet/src/wallet/managed_wallet_info/mod.rs, key-wallet/src/wallet/managed_wallet_info/wallet_info_interface.rs, key-wallet/src/wallet/managed_wallet_info/coin_selection.rs, key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs, key-wallet/src/wallet/managed_wallet_info/helpers.rs	Removed unused alloc::{string::String, vec::Vec} imports. Switched BTreeSet from alloc to std. Removed feature gating from error trait implementations.
Wallet Core and Misc key-wallet/src/wallet/mod.rs, key-wallet/src/wallet/helper.rs, key-wallet/src/wallet/bip38.rs, key-wallet/src/seed.rs, key-wallet/src/transaction_checking/account_checker.rs, key-wallet/src/tests/wallet_tests.rs, key-wallet-manager/src/wallet_manager/mod.rs, key-wallet-manager/src/wallet_manager/process_block.rs	Removed unused alloc::{string::String, vec::Vec, ToString} imports. Updated collection type sources from alloc to std.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~55 minutes

Poem

🐰 From alloc we hop to std, a grand migration,
No features to gate, just one configuration,
Error traits now shine unconditionally bright,
The wallet is standard, our systems feel light!
✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main objective of the PR: removing no-std support from the key-wallet crate, which aligns with the extensive changes across the codebase.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ 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 chore/drop-nostd-supp-key-wallet

📝 Coding Plan

• Generate coding plan for human review comments

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.11%. Comparing base (665bb7b) to head (eb5b21b).
⚠️ Report is 1 commits behind head on v0.42-dev.

Additional details and impacted files

@@              Coverage Diff              @@
##           v0.42-dev     #518      +/-   ##
=============================================
- Coverage      66.35%   66.11%   -0.25%     
=============================================
  Files            311      311              
  Lines          64979    64988       +9     
=============================================
- Hits           43116    42964     -152     
- Misses         21863    22024     +161     

Flag	Coverage Δ
core	75.13% <ø> (ø)
ffi	35.95% <ø> (-1.59%)	⬇️
rpc	28.28% <ø> (ø)
spv	81.15% <ø> (+0.07%)	⬆️
wallet	65.90% <100.00%> (-0.04%)	⬇️

Files with missing lines	Coverage Δ
key-wallet-manager/src/wallet_manager/mod.rs	49.00% <ø> (ø)
...wallet-manager/src/wallet_manager/process_block.rs	48.97% <ø> (ø)
key-wallet/src/account/account_collection.rs	57.17% <ø> (ø)
key-wallet/src/account/account_trait.rs	21.42% <ø> (ø)
key-wallet/src/account/bls_account.rs	53.82% <ø> (ø)
key-wallet/src/account/eddsa_account.rs	56.48% <ø> (ø)
key-wallet/src/bip32.rs	80.19% <ø> (-0.45%)	⬇️
key-wallet/src/bip38.rs	1.46% <ø> (ø)
key-wallet/src/derivation.rs	75.75% <ø> (ø)
key-wallet/src/derivation_bls_bip32.rs	91.54% <ø> (ø)
... and 30 more

... and 18 files with indirect coverage changes

[github-actions]

This PR has merge conflicts with the base branch. Please rebase or merge the base branch into your branch to resolve them.

[github-actions]

This PR has merge conflicts with the base branch. Please rebase or merge the base branch into your branch to resolve them.