fix: make snapshot diffs resilient on Windows

[noobezlol]

Issue

Fixes #12474

Context

Snapshot generation requested effectively unlimited unified-diff context. On Windows, Git can emit malformed persisted patches for multi-hunk changes. The VS Code session diff source also allowed one parser exception to abort the complete diff response, leaving the Changes panel at 0 files changed even when other file patches were valid.

Implementation

• Generate snapshot patches with bounded --unified=3 context.
• Isolate patch parsing per file so one malformed persisted patch cannot hide valid files.
• Preserve malformed text patches as summarized entries rather than discarding them.
• Add regression coverage for distant bounded hunks and mixed malformed/valid session patches.
• Add patch changesets for the CLI and VS Code extension.

Screenshots / Video

N/A — this changes snapshot generation and error recovery behavior without changing the UI layout.

How to Test

Manual/local verification

• CLI snapshot regression suite: 9 passed.
• VS Code session diff source suite: 13 passed.
• CLI and VS Code typechecks passed.
• Repository lint, formatting, Knip, annotations, changeset validation, and git diff --check passed.
• The pre-push monorepo typecheck passed for all 22 non-JetBrains packages.

Reviewer test steps

1. On Windows, create a session that modifies multiple files with distant hunks.
2. Open the Changes panel and confirm all generated snapshot patches render.
3. Replace one persisted file patch with malformed unified-diff text.
4. Confirm other files remain visible and the malformed file is retained as a summarized entry.

Blocked checks and substitute verification

• The JetBrains-only pre-push typecheck could not configure Gradle because the local /usr/lib/jvm/java-25-openjdk installation does not provide JAVA_COMPILER. This PR does not touch JetBrains code; the affected CLI and VS Code typechecks and targeted regression suites passed.
• The full VS Code unit suite completed with 3,292 passing and 9 unrelated environment-sensitive failures. The changed session-diff source suite passes independently.

Checklist

• Issue linked above, or exception explained
• Tests/verification described
• Screenshots/video included for visual changes, or marked N/A
• Changeset considered for user-facing changes

Get in Touch

GitHub: @noobezlol

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (5 files)

• .changeset/safe-windows-snapshot-diffs.md
• packages/kilo-vscode/src/diff/sources/session.ts
• packages/kilo-vscode/tests/unit/diff-session-source.test.ts
• packages/opencode/src/kilocode/snapshot/diff-full.ts
• packages/opencode/test/kilocode/diff-full.test.ts

---

_{Reviewed by claude-sonnet-5 · Input: 32 · Output: 8.7K · Cached: 792.9K}

_{Review guidance: REVIEW.md from base branch main}

[marius-kilocode]

Thanks for the fix! Verified end to end: new snapshots persist bounded hunks, and with a deliberately corrupted patch in session_diff storage the Changes panel keeps the file listed with its stats as a summarized entry instead of emptying to 0 files changed. Both layers do exactly what the description says. Nice work.

[noobezlol]

Hi! I'm noobezlol. I have 3 merged PRs and 6 open PRs. I think I qualify for the Contributor role, but I only see the inactive #kilo-dev-contributors channel. Is there another contributor channel or someone who can grant access? Thanks!