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/constants.js

@@ -4,6 +4,7 @@ export const MIN_COMPRESS_SIZE = 500;          // bytes; skip tiny blobs
 export const DETECT_WINDOW = 1024;             // autodetect peeks first N chars
 export const GIT_DIFF_HUNK_MAX_LINES = 100;    // per-hunk line cap
 export const GIT_DIFF_CONTEXT_KEEP = 3;        // context lines around changes
+export const GIT_LOG_MAX_LINES = 200;          // gitLog line cap
 export const DEDUP_LINE_MAX = 2000;            // dedupLog truncation cap
 
 // Rust pipe_cmd.rs parity caps