[chokri29]

Urgent F1 compiler fix

Changes

• Discover compiler candidates from solc-select inventory, artifact directories, and solc --version on PATH, but only report/select versions that resolve to an executable binary.
• Select the highest installed compiler compatible with a pragma such as ^0.8.0; use the highest installed compiler for no-pragma sources.
• Never return a missing requested compiler as if it were installed. Health now reports compilers_ready only when a usable compiler binary is verified and exposes the effective default.
• Prefer Slither Python API. On solc X not installed / only Y available, retry the Python API exactly once using a verified installed compiler, activate it with solc-select use, and pin the temporary source pragma to that version.
• Do not fall back to the Slither CLI after a Python API compile error (avoids the known argparse failure path).
• Align Docker/default guidance to SOLC_VERSION=0.8.38; Docker installs and selects 0.8.38.
• Remove the duplicate legacy compiler selector from solc_patch.py and delegate to solc_util.py.
• Add regression tests for verified compiler discovery, caret pragma selection, no-pragma selection, and source pinning.

Validation

• Source changes and test coverage added.
• I have not run the GitHub Actions suite or exercised the live Render deployment from this environment. The acceptance test still required after deployment is the Reentrancy sample showing F1 → F2 → F3, at least one Slither signal, and grounded findings.

Render environment

Set SOLC_VERSION=0.8.38 in the Render service environment and remove any SOLC_VERSION=0.8.0 setting. Do not expose or paste API keys.