perf(vscode): exclude patch from diff hash to reduce memory overhead (#8967)

* perf(vscode): exclude patch from diff hash to reduce memory overhead

The hashFileDiffs function included diff.patch in its hash key, pulling
in multi-MB payloads generated by opencode's context: MAX_SAFE_INTEGER
setting. The extension never renders the patch string — VS Code's native
diff editor uses before/after file contents instead — so the field was
pure overhead.

Closes #8951

* chore(kilo-docs): update source links

packages/kilo-docs/source-links.md

@@ -1,7 +1,7 @@
 # Source Code Links
 
 <!-- Auto-generated by script/extract-source-links.ts — DO NOT EDIT -->
-<!-- 79 unique URLs extracted from extension and CLI source -->
+<!-- 80 unique URLs extracted from extension and CLI source -->
 
 - <https://api.apertis.ai/v1>
   <!-- packages/opencode/src/provider/model-cache.ts -->
@@ -55,6 +55,8 @@
   <!-- packages/kilo-vscode/webview-ui/src/components/settings/AboutKiloCodeTab.tsx -->
 - <https://github.com/Kilo-Org/kilocode/issues/6986>
   <!-- packages/kilo-vscode/src/agent-manager/constants.ts -->
+- <https://github.com/Kilo-Org/kilocode/issues/8951>
+  <!-- packages/kilo-vscode/src/review-utils.ts -->
 - <https://github.com/Kilo-Org/kilocode/issues/new?template=bug-report.yml>
   <!-- packages/opencode/src/cli/cmd/tui/app.tsx -->
 - <https://github.com/Kilo-Org/kilocode/issues/new/choose>

packages/kilo-vscode/src/review-utils.ts

@@ -42,6 +42,19 @@ export async function resolveLocalDiffTarget(
   return { directory: root, baseBranch: base }
 }
 
+/**
+ * Produces a lightweight hash key for a list of file diffs.
+ *
+ * Intentionally excludes `diff.patch` — the extension never renders the
+ * unified-diff patch string (VS Code's native diff editor uses before/after
+ * file contents instead). Including it would pull in multi-MB payloads
+ * generated by opencode's `context: MAX_SAFE_INTEGER` setting, inflating
+ * memory for no benefit. The remaining fields (file, status, additions,
+ * deletions, tracked, generatedLike, summarized, stamp) are sufficient to
+ * detect when the diff list has meaningfully changed.
+ *
+ * See: https://github.com/Kilo-Org/kilocode/issues/8951
+ */
 export function hashFileDiffs(
   diffs: Array<
     SnapshotFileDiff & {
@@ -54,7 +67,6 @@ export function hashFileDiffs(
 ): string {
   return diffs
     .map((diff) => {
-      const content = diff.summarized ? "" : diff.patch
       return [
         diff.file,
         diff.status,
@@ -64,7 +76,6 @@ export function hashFileDiffs(
         diff.generatedLike ? "generated" : "source",
         diff.summarized ? "summary" : "detail",
         diff.stamp ?? "",
-        content,
       ].join(":")
     })
     .join("|")