fix: traverse up to discover compilation framework config

[cats2101]

Closes #538.

When the target is a single Solidity file and crytic-compile falls back to the Solc platform, the code used to check only the working directory for a known compilation framework (Foundry, Hardhat, ...). If the user invoked crytic-compile from a subdirectory of their project, the framework was not detected and remappings / solc version were silently dropped.

This walks up the directory tree from the working directory and accepts the first ancestor that matches a non-Solc platform, then passes that directory to platform.config(...) so the framework is queried at its actual root.

Foundry already traverses upwards inside Foundry.locate_project_root, so it was unaffected. Hardhat/Truffle/Dapp/Brownie/Waffle/Embark/Buidler/Etherlime only check the literal path they're given — those are the cases this change actually fixes.

Changes

• Extract the detection into a _locate_framework_root helper that walks up from the working directory.
• Use the directory where the platform was detected (not the original working directory) when calling platform.config(...), so framework-specific subprocesses (e.g. forge config --json) run at the project root.

Tests

Added tests/test_locate_framework_root.py covering:

• Hardhat detection from a nested subdirectory
• Foundry detection at the project root
• (None, None) when no framework is present up to /
• hardhat_ignore kwarg disables detection

Pre-existing tests/test_library_linking.py and tests/test_sourcify_proxy.py failures on my machine are unrelated (solc binary architecture mismatch in solc-select) and reproduce on master.

[cats2101]

Gentle ping — anything else needed here?