fix: base path resolution fallback when git root is unavailable (#2236)

* updates

* fix: base path resolution fallback when git root is unavailable

Make tryResolveWithGitRoot and tryResolveWithConfigPath source-aware by
passing the source parameter through the call chain. For runtime sources
(ATMOS_BASE_PATH env var, --base-path flag, atmos_base_path provider
param), tryResolveWithConfigPath now tries CWD first before config dir.
Both paths use os.Stat validation with fallback.

This fixes "failed to find import" on CI workers without .git where the
v1.210.1 os.Stat fallback in tryResolveWithGitRoot was bypassed because
getGitRootOrEmpty returned empty.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address CodeRabbit review feedback on PR #2236

- Clarify pre-fix vs post-fix wording in fix doc references section
- Add cross-dependency to multiple abstract components cycle test
- Log permission/access errors in tryCWDRelative for parity with tryResolveWithGitRoot

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aknysh