feat: enhance file history range tracking with comprehensive overlap handling

[KJ7LNW]

Context

This PR significantly improves the file history range tracking system to handle complex overlapping scenarios that were previously causing issues with redundant file reads and incorrect range calculations.

Implementation

Enhanced Range Detection:

• Added computeModifiedRanges() function for precise line-by-line change detection
• Added adjustHistoricalRanges() for proper range adjustment after content modifications
• Added getChangedLineRanges() for comprehensive diff analysis

Improved calculateWriteRanges() Logic:

• Now compares original vs modified content instead of marking entire files as valid
• Properly preserves historical valid ranges while only invalidating actually modified ranges
• Handles complex scenarios like range splitting, merging, and line number shifts

Comprehensive Test Coverage:

• Partial Overlap Tests: Left/right edge overlaps, multiple range overlaps
• Separation Tests: Insertions between ranges, boundary insertions
• Complete Coverage Tests: Entire range replacements, extensions beyond ranges
• Edge Cases: File start/end modifications, empty files, adjacent ranges
• Complex Scenarios: Multi-range modifications, non-contiguous changes

How to Test

1. Run the comprehensive test suite:

   cd src && npx vitest core/file-history/__tests__/fileHistoryUtils.spec.ts

2. Test various file modification scenarios:

   • Modify portions of previously read files
   • Insert content between existing ranges
   • Make overlapping modifications across multiple ranges
   • Verify only modified ranges are invalidated

Benefits

• Prevents redundant reads: Only re-reads actually modified content ranges
• Accurate range tracking: Preserves valid historical ranges through complex modifications
• Robust overlap handling: Correctly handles all types of range intersections and splits
• Mathematical precision: Range calculations validated through comprehensive test scenarios

Fixes #5871 #1374

---

Important

Enhances file history range tracking with precise overlap handling and updates tools to utilize these improvements.

• Behavior:
  • Adds computeModifiedRanges(), adjustHistoricalRanges(), and getChangedLineRanges() in fileHistoryUtils.ts for precise range detection and adjustment.
  • Improves calculateWriteRanges() to compare original vs modified content, preserving valid ranges and handling complex scenarios.
  • Updates tools like writeToFileTool, insertContentTool, and readFileTool to use enhanced range tracking.
• Tests:
  • Adds comprehensive tests in fileHistoryUtils.spec.ts for partial overlaps, complete coverage, edge cases, and complex scenarios.
• Misc:
  • Adds FileLineRange and FileMetadata interfaces to apiMessages.ts.
  • Updates Task.ts to track file modification times and manage pending file metadata.

^{This description was created by for 79fcc89b2986484f1760f08ab14d12b511cc7429. You can customize this summary. It will automatically update as commits are pushed.}

[KJ7LNW]

@daniel-lxs this fixes the underlying readfile problem.

you should probably run an eval and make sure there are no surprises

[daniel-lxs]

I fixed the merge conflicts but it seems like something is wrong with the file detection if the file is changed:

I'm guessing it has to do with empty lines in the file remaining unchanged, how do you think we should handle this?

[KJ7LNW]

I'm guessing it has to do with empty lines in the file remaining unchanged, how do you think we should handle this?

if the line did not actually change, then they can be omitted. I have a feeling that the code that scans to see if lines change is somehow misbehaving on lines that are "falsy"