feat(rtk): add JS-native git-log filter (#2423)

Compress git log output via dedicated RTK filter: keep commit headers,
Author/Date, subject; drop body padding, decoration, embedded diff lines.
Wire into autodetect (git-log prioritized before git-diff) and registry.

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/rtk/filters/gitLog.js

@@ -0,0 +1,99 @@
+// JS-native git-log filter
+// Compresses `git log` output: keeps commit headers, subjects, Author/Date;
+// drops body padding, decoration, embedded diff lines.
+import { GIT_LOG_MAX_LINES } from "../constants.js";
+
+export function gitLog(text, maxLines = GIT_LOG_MAX_LINES) {
+  if (!text) return "";
+
+  const input = String(text);
+  const lines = input.split("\n");
+  const out = [];
+  let skipped = 0;
+  let inCommit = false;
+  let subjectSeen = false;
+
+  function pushLine(l) {
+    if (out.length < maxLines) {
+      out.push(l);
+      return true;
+    }
+    skipped++;
+    return false;
+  }
+
+  for (let i = 0; i < lines.length; i++) {
+    const raw = lines[i];
+    const line = raw.trimEnd();
+    const trimmed = line.trim();
+
+    // commit <sha> header — starts new commit entry
+    // Also matched with leading graph decoration (`*   commit abc1234...` — --graph without --oneline)
+    if (/^commit [0-9a-f]{7,40}$/i.test(trimmed) || /^[*|/\\ ]+commit [0-9a-f]{7,40}/i.test(trimmed)) {
+      inCommit = true;
+      subjectSeen = false;
+      pushLine(line);
+      continue;
+    }
+
+    if (inCommit) {
+      // Author / Date — keep as-is (already column 0 in raw, or graph-prefix stripped by commit-header match)
+      if (/^[*|/\\ ]*(Author|Date):/i.test(trimmed)) {
+        pushLine(trimmed);
+        continue;
+      }
+      // blank — skip
+      if (trimmed === "") continue;
+      // indented subject (4 spaces, optionally preceded by graph decoration) — first one is subject
+      if (!subjectSeen && /^[*|/\\ ]*    \S/.test(line)) {
+        pushLine("  Subject: " + trimmed);
+        subjectSeen = true;
+        continue;
+      }
+      // stat summary: "N file(s) changed, N insertions(+), N deletions(-)"
+      if (/^\d+ file\w* changed/.test(trimmed)) {
+        pushLine("  " + trimmed);
+        continue;
+      }
+      // embedded diff header — one-line marker
+      if (/^diff --git /.test(trimmed)) {
+        pushLine("  ... diff body omitted");
+        continue;
+      }
+      // everything else in commit body — drop
+      continue;
+    }
+
+    // Not in a commit block (--oneline / --graph modes):
+
+    // Graph decoration + sha + subject: "*|/\\ <sha7> <subject>"
+    const graphMatch = trimmed.match(/^[*|/\\ ]+([0-9a-f]{7,40}\s+.+)/i);
+    if (graphMatch) {
+      pushLine(graphMatch[1]);
+      continue;
+    }
+
+    // Plain oneline: "<sha7> <subject>"
+    if (/^[0-9a-f]{7,40}\s+/.test(trimmed)) {
+      pushLine(trimmed);
+      continue;
+    }
+
+    // Pure graph decoration (no sha) — drop
+    if (/^[*|/\\ ]+$/.test(trimmed) && /[*|/\\]/.test(trimmed)) {
+      continue;
+    }
+
+    // catch-all pass-through
+    pushLine(trimmed);
+  }
+
+  if (skipped > 0) out.push(`... (${skipped} more lines)`);
+
+  const result = out.join("\n");
+  if (!result && input) return input;
+  if (result.length > input.length) return input;
+  return result;
+}
+
+gitLog.filterName = "git-log";