feat: integrate Pi backend and Pi Web

pi-web/lib/compaction-summary.ts

@@ -0,0 +1,34 @@
+export interface ParsedCompactionSummary {
+  body: string;
+  readFiles: string[];
+  modifiedFiles: string[];
+}
+
+const FILE_SECTION_RE = /<(read-files|modified-files)>\s*([\s\S]*?)\s*<\/\1>/g;
+const TRAILING_FILE_SECTIONS_RE = /(?:\r?\n){2,}((?:[ \t]*<(?:read-files|modified-files)>[ \t]*\r?\n[\s\S]*?\r?\n[ \t]*<\/(?:read-files|modified-files)>[ \t]*(?:\r?\n)?)+)\s*$/;
+
+export function parseCompactionSummary(summary: string): ParsedCompactionSummary {
+  const readFiles: string[] = [];
+  const modifiedFiles: string[] = [];
+  const metadataMatch = summary.match(TRAILING_FILE_SECTIONS_RE);
+  const metadataBlock = metadataMatch?.[1] ?? "";
+  const body = metadataMatch?.index === undefined ? summary : summary.slice(0, metadataMatch.index);
+
+  metadataBlock.replace(FILE_SECTION_RE, (_match, section: string, content: string) => {
+    const files = content
+      .split(/\r?\n/)
+      .map((line) => line.trim())
+      .filter(Boolean);
+
+    if (section === "read-files") readFiles.push(...files);
+    else modifiedFiles.push(...files);
+
+    return "";
+  });
+
+  return {
+    body: body.trim(),
+    readFiles,
+    modifiedFiles,
+  };
+}