Add image scope scanning option to the Linux detector

[grvillic]

Reverts #1613

Add the ability to configure the image scanning scope used by Syft for the Linux detector.

This allows your to pass in the argument --DetectorArgs Linux.ImageScanScope=squashed to have the detector invoke Syft with --scope squashed instead of the default of --scope all-layers.

If components from all layers are not needed, squashed has significant performance benefits.

[codecov]

Codecov Report

❌ Patch coverage is 98.23009% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.2%. Comparing base (e2c9188) to head (65075f5).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ion.Detectors.Tests/LinuxContainerDetectorTests.cs	93.5%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##            main   #1621    +/-   ##
======================================
  Coverage   90.2%   90.2%            
======================================
  Files        437     437            
  Lines      37801   37905   +104     
  Branches    2324    2330     +6     
======================================
+ Hits       34121   34228   +107     
+ Misses      3203    3199     -4     
- Partials     477     478     +1     

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[Copilot]

Pull request overview

Adds a configurable Syft image scanning scope to the Linux detector so callers can switch from the default all-layers scan to squashed for improved performance when scanning all layers isn’t needed.

Changes:

• Introduces LinuxScannerScope and threads it through LinuxContainerDetector -> ILinuxScanner -> LinuxScanner to control Syft’s --scope flag.
• Parses Linux.ImageScanScope from --DetectorArgs (defaulting to all-layers) and adds/updates unit tests for scope handling.
• Documents the new detector argument in the Linux detector docs.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/Microsoft.ComponentDetection.Detectors.Tests/LinuxScannerTests.cs	Updates existing calls to include scope and adds tests asserting correct --scope flag behavior.
test/Microsoft.ComponentDetection.Detectors.Tests/LinuxContainerDetectorTests.cs	Adds coverage ensuring detector args drive the scope passed into the scanner.
src/Microsoft.ComponentDetection.Detectors/linux/LinuxScannerScope.cs	Defines the new scope enum (AllLayers, Squashed).
src/Microsoft.ComponentDetection.Detectors/linux/LinuxScanner.cs	Builds the Syft command using scope-specific arguments and validates enum values.
src/Microsoft.ComponentDetection.Detectors/linux/LinuxContainerDetector.cs	Reads Linux.ImageScanScope from detector args and passes it through the scan pipeline.
src/Microsoft.ComponentDetection.Detectors/linux/ILinuxScanner.cs	Extends the scanner interface to accept the new scope parameter.
docs/detectors/linux.md	Documents the new Linux.ImageScanScope argument and its expected values.

[github-actions]

👋 Hi! It looks like you modified some files in the Detectors folder.
You may need to bump the detector versions if any of the following scenarios apply:

• The detector detects more or fewer components than before
• The detector generates different parent/child graph relationships than before
• The detector generates different devDependencies values than before

If none of the above scenarios apply, feel free to ignore this comment 🙂