APT multi-arch package parsing creates empty package names

Read manager/apt/utils.go to trace ParseFindOutput and ParseDpkgQueryOutput, then inspect the related cases in manager/apt/utils_test.go. Run the APT parser tests first and add coverage for packages installed under multiple architectures. Done means both architecture-specific packages retain distinct names and no empty package entry is produced.

Summary

APT search results occasionally show entries with empty package names (e.g., : [version][] (installed)) when multi-architecture packages are installed.

Root Cause Analysis

The issue occurs when dpkg returns multiple architectures for the same package (e.g., libcurl4:amd64 and libcurl4:i386), but our search parsing only finds one entry.

Technical Details

1. APT search finds: libcurl4/jammy-updates,jammy-security,now 7.81.0-1ubuntu1.20 amd64 [installed]
2. Parsed as: {Name: "libcurl4", Arch: "amd64"}
3. dpkg-query returns TWO packages: libcurl4:amd64 AND libcurl4:i386
4. First processing: Finds libcurl4 in map, processes correctly, deletes from map
5. Second processing: Can't find libcurl4 in map (already deleted), creates empty PackageInfo

Current Impact

• Frequency: <0.1% of packages affected
• Severity: Cosmetic only - no functional impact
• Example Output: : [7.81.0-1ubuntu1.20][] (installed)

Proposed Solution

Implement proper multi-arch support by using name:arch as the key throughout the parsing pipeline:

Changes Required

1. ParseFindOutput: Use name:arch as dictionary key instead of just name
2. ParseDpkgQueryOutput: Parse architecture from dpkg output and use matching key
3. Display: Show multi-arch packages as package:arch (e.g., libcurl4:amd64)

Benefits

• ✅ Eliminates cosmetic parsing bug
• ✅ Provides accurate multi-arch representation
• ✅ Matches APT's actual behavior
• ✅ Useful for debugging multi-arch dependency issues

Implementation Notes

• Scope: APT-specific (other package managers already handle this correctly)
• Breaking Changes: None - just improved accuracy
• Files: manager/apt/utils.go, manager/apt/utils_test.go
• Complexity: Low - ~20 lines of changes

Test Cases

# Before fix
apt: libcurl4 [version][version] (installed)
:  [version][] (installed)  # ← Bug

# After fix  
apt: libcurl4:amd64 [version][version] (installed)
apt: libcurl4:i386 [version][version] (installed)

Priority

Low - This is a cosmetic issue that doesn't affect core functionality. The system works correctly for 99.9%+ of packages.

Labels

• enhancement
• apt
• parsing
• multi-arch