Add unified Minotari Ledger installer

[tzmWW]

Fixes #7795

Summary

• Add one cross-platform Python installer for the Minotari Ledger Wallet app.
• Detect supported Ledger devices with ledgerwallet target IDs and report the original Nano S as unsupported.
• Resolve a matching Tari release artifact, verify the .zip.sha256 sidecar, and safely extract the archive.
• Install current minotari_ledger_wallet.apdu artifacts directly, with app_*.json/app_*.toml manifest fallback for older archives.
• Keep the existing per-model scripts as thin compatibility wrappers around the unified installer.

Correctness Note

The current stable Tari release does not include Ledger wallet assets, while v5.4.0-pre.1 does. The default lookup scans recent non-draft releases, including pre-releases, so the installer can find the newest usable Ledger artifact instead of stopping at a release with no matching assets.

Testing

• uv run python applications/minotari_ledger_wallet/wallet/install_scripts/test_install_minotari_ledger.py
• uv run python applications/minotari_ledger_wallet/wallet/install_scripts/install_minotari_ledger.py --help
• uv run python -m py_compile applications/minotari_ledger_wallet/wallet/install_scripts/install_minotari_ledger.py applications/minotari_ledger_wallet/wallet/install_scripts/test_install_minotari_ledger.py
• uvx ruff check applications/minotari_ledger_wallet/wallet/install_scripts/install_minotari_ledger.py applications/minotari_ledger_wallet/wallet/install_scripts/test_install_minotari_ledger.py
• git diff --check
• Live release lookup confirmed v5.4.0-pre.1 assets and checksum sidecars for nanosplus, nanox, stax, and flex.

[gemini-code-assist]

Code Review

This pull request introduces a unified Python-based installer (install_minotari_ledger.py) along with unit tests to replace the previous model-specific shell and PowerShell scripts, which are now thin compatibility wrappers. The reviewer provided valuable feedback identifying three key issues in the new installer: a process replacement issue on Windows when using os.execve that causes overlapping shell output, a security vulnerability in parse_sha256_file where incorrect checksums could pass verification under certain conditions, and a potential crash if the Content-Length header contains an invalid integer. Addressing these issues will significantly improve the installer's robustness, security, and cross-platform compatibility.

[tzmWW]

Updated the branch:

• Replaced custom raw APDU replay with ledgerblue.runScript --scp in install_minotari_ledger.py
• Removed the custom APDU parser/sender and status-word handling code.
• Kept ledgerwallet target-ID detection for robustness.

Tests:

• Tested the installation process on a Ledger Nano S Plus. Downloaded and verified v5.4.0-pre.2
• An outdated firmware makes the installation fail, so made sure the user is correctly prompted.

[tzmWW]

Update:

• Simplified workflow structure: removed legacy manifest fallback and old --model flag to avoid unwanted overrides.
• Fixed asset-selection bug: same-model zips without .sha256 are skipped instead of blocking valid later assets. This is a tiny fix that add robustness for future releases.
• Additional errors during installation are now wrapped in InstallerErrors for correct error handling and user prompting.
• Updated installer docs and test suite accordingly.